MAXIM DS21348, DS21Q348 User Manual

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FEATURES

DS21348/DS21Q348

3.3V E1/T1/J1 Line Interface

PIN CONFIGURATIONS

 Complete E1, T1, or J1 Line Interface Unit

(LIU)

 Supports Both Long-Haul And Short-Haul

Trunks

 Internal Software-Selectable Receive-Side

Termination for 75Ω/100Ω/120Ω

 3.3V Power Supply  32-Bit or 128-Bit Crystal-Less Jitter

Attenuator Requires Only a 2.048MHz Master Clock for Both E1 and T1 with Option to Use 1.544MHz for T1

 Generates the Appropriate Line Build-Outs,

with and without Return loss, for E1 and DSX-1 and CSU Line Build-Outs for T1

 AMI, HDB3, and B8ZS, Encoding/Decoding  16.384MHz, 8.192MHz, 4.096MHz, or

2.048MHz Clock Output Synthesized to Recovered Clock

 Programmable Monitor Mode for Receiver  Loopbacks and PRBS Pattern Generation/

Detection with Output for Received Errors

 Generates/Detects In-Band Loop Codes,

1 to 16 Bits Including CSU Loop Codes

 8-Bit Parallel or Serial Interface with

Optional Hardware Mode

 Muxed and Nonmuxed Parallel Bus Supports

Intel or Motorola

 Detects/Generates Blue (AIS) Alarms  NRZ/Bipolar Interface for Tx/Rx Data I/O  Transmit Open-Circuit Detection  Receive Carrier Loss (RCL) Indication

(G.775)

 High-Impedance State for TTIP and TRING  50mA (RMS) Current Limiter

TOP VIEW

DS21348

44 TQFP

DS21Q348

49 CSBGA

(7mm x 7mm)

See Section 8 for 144-pin CSBGA pinout.

ORDERING INFORMATION

PART CHANNEL

DS21348TN Single -40°C to +85°C 44 TQFP

DS21348TN+ Single -40°C to +85°C 44 TQFP

DS21348T Single 0°C to +70°C 44 TQFP DS21348T+ Single 0°C to +70°C 44 TQFP DS21348GN Single -40°C to +85°C 49 CSBGA

DS21348GN+ Single -40°C to +85°C 49 CSBGA DS21348G Single 0°C to +70°C 49 CSBGA DS21348G+ Single 0°C to +70°C 49 CSBGA

DS21Q348N Four -40°C to +85°C 144 CSBGA DS21Q348 Four 0°C to +70°C 144 CSBGA

+ Denotes lead-free/RoHS-compliant package.

TEMP

RANGE

PIN-PACKAGE

Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata

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DS21348/DS21Q348

DETAILED DESCRIPTION

The DS21348 is a complete selectable E1 or T1 line interface unit (LIU) for short-haul and long-haul applications. Throughout the data sheet, J1 is represented wherever T1 exists. Receive sensitivity adjusts automatically to the incoming signal and can be programmed for 0dB to 12dB or 0dB to 43dB for E1 applications and 0dB to 30dB or 0dB to 36dB for T1 applications. The device can generate the necessary G.703 E1 waveshapes in 75Ω or 120Ω applications and DSX-1 line build-outs or CSU line build-outs of 0dB, -7.5dB, -15dB, and -22.5dB for T1 applications. The crystal-less on-board jitter attenuator requires only a 2.048MHz MCLK for both E1 and T1 applications (with the option of using a 1.544MHz MCLK in T1 applications). The jitter attenuator FIFO is selectable to either 32 bits or 128 bits in depth and can be placed in either the transmit or receive data paths. An X 2.048MHz output clock synthesized to RCLK is available for use as a backplane system clock (where n = 1, 2, 4, or 8).

The DS21348 has diagnostic capabilities such as loopbacks and PRBS pattern generation/detection. 16bit loop-up and loop-down codes can be generated and detected. The device can be controlled through an 8-bit parallel muxed or nonmuxed port, serial port, or used in hardware mode. The device fully meets all of the latest E1 and T1 specifications including ANSI T1.403-1999, ANSI T1.408, AT&T TR 62411, ITU G.703, G.704, G.706, G.736, G.775, G.823, I.431, O.151, O.161, ETSI ETS 300 166, JTG.703, JTI.431, JJ-20.1, TBR12, TBR13, and CTR4.

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DS21348/DS21Q348

1. INTRODUCTION.................................................................................................................. 6

1.1 DOCUMENT REVISION HISTORY...............................................................................................6

2. PIN DESCRIPTION............................................................................................................ 10

2.1 PIN DESCRIPTIONS ........................................................................................................................14

3. HARDWARE MODE .......................................................................................................... 25

3.1 REGISTER MAP .............................................................................................................................25

3.2 PARALLEL PORT OPERATION .........................................................................................................26

3.3 SERIAL PORT OPERATION..............................................................................................................26

4. CONTROL REGISTERS.................................................................................................... 29

4.1 DEVICE POWER-UP AND RESET .....................................................................................................32

5. STATUS REGISTERS ....................................................................................................... 36

6. DIAGNOSTICS .................................................................................................................. 41

6.1 IN-BAND LOOP CODE GENERATION AND DETECTION ......................................................................41

6.2 LOOPBACKS ..................................................................................................................................46

6.2.1 Remote Loopback (RLB) .....................................................................................................................46

6.2.2 Local Loopback (LLB) .......................................................................................................................... 46

6.2.3 Analog Loopback (ALB) ....................................................................................................................... 46

6.2.4 Dual Loopback (DLB)........................................................................................................................... 46

6.3 PRBS GENERATION AND DETECTION ............................................................................................47

6.4 ERROR COUNTER..........................................................................................................................47

6.4.1 Error Counter Update........................................................................................................................... 48

6.5 ERROR INSERTION ........................................................................................................................48

7. ANALOG INTERFACE ...................................................................................................... 49

7.1 RECEIVER .....................................................................................................................................49

7.2 TRANSMITTER ...............................................................................................................................50

7.3 JITTER ATTENUATOR .....................................................................................................................50

7.4 G.703 SYNCHRONIZATION SIGNAL .................................................................................................51

8. DS21Q348 QUAD LIU ....................................................................................................... 58

9. DC CHARACTERISTICS................................................................................................... 62

10. THERMAL CHARACTERISTICS....................................................................................... 63

11. AC CHARACTERISTICS................................................................................................... 64

12. PACKAGE INFORMATION ............................................................................................... 73

12.1 44-PIN TQFP (56-G4012-001) .....................................................................................................73

12.2 49-BALL CSGBA (7MM X 7MM) (56-G6006-001) ...........................................................................74

12.3 144-BALL CSBGA (17MM X 17MM) (56-G6011-001) .....................................................................75

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DS21348/DS21Q348

LIST OF FIGURES

Figure 1-1. DS21348 Block Diagram..........................................................................................................7

Figure 1-2. Receive Logic...........................................................................................................................8

Figure 1-3. Transmit Logic..........................................................................................................................9

Figure 2-1. Parallel Port Mode Pinout (BIS1 = 0, BIS0 = 1 or 0) (TQFP Package) .................................. 22

Figure 2-2. Serial Port Mode Pinout (BIS1 = 1, BIS0 = 0) (TQFP Package) ............................................ 23

Figure 2-3. Hardware Mode Pinout (BIS1 = 1, BIS0 = 1) (TQFP Package) .............................................24

Figure 3-1. Serial Port Operation for Read Access (R = 1) Mode 1 ......................................................... 27

Figure 3-2. Serial Port Operation for Read Access Mode 2 .....................................................................27

Figure 3-3. Serial Port Operation for Read Access Mode 3 .....................................................................27

Figure 3-4. Serial Port Operation for Read Access Mode 4 .....................................................................28

Figure 3-5. Serial Port Operation for Write Access (R = 0) Modes 1 and 2..............................................28

Figure 3-6. Serial Port Operation for Write Access (R = 0) Modes 3 and 4..............................................28

Figure 7-1. Basic Interface .......................................................................................................................52

Figure 7-2. Protected Interface Using Internal Receive Termination........................................................ 53

Figure 7-3. Protected Interface Using External Receive Termination.......................................................54

Figure 7-4. E1 Transmit Pulse Template..................................................................................................55

Figure 7-5. T1 Transmit Pulse Template ..................................................................................................56

Figure 7-6. Jitter Tolerance ......................................................................................................................57

Figure 7-7. Jitter Attenuation .................................................................................................................... 57

Figure 8-1. 144-CSBGA (17mm x 17mm) Pinout .....................................................................................61

Figure 11-1. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 0) ....................................................... 65

Figure 11-2. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 0) .......................................................65

Figure 11-3. Motorola Bus Timing (PBTS = 1, BIS1 = 0, BIS0 = 0).......................................................... 66

Figure 11-4. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 1) ....................................................... 68

Figure 11-5. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 1) .......................................................68

Figure 11-6. Motorola Bus Read Timing (PBTS = 1, BIS1 = 0, BIS0 = 1) ................................................69

Figure 11-7. Motorola Bus Write Timing (PBTS = 1, BIS1 = 0, BIS0 = 1) ................................................ 69

Figure 11-8. Serial Bus Timing (BIS1 = 1, BIS0 = 0)................................................................................70

Figure 11-9. Receive Side Timing ............................................................................................................71

Figure 11-10. Transmit Side Timing .........................................................................................................72

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DS21348/DS21Q348

LIST OF TABLES

Table 2-1. Bus Interface Selection ...........................................................................................................10

Table 2-2. Pin Assignment in Parallel Port Mode .....................................................................................10

Table 2-3. Pin Assignment in Serial Port Mode........................................................................................11

Table 2-4. Pin Assignment in Hardware Mode .........................................................................................12

Table 2-5. Pin Descriptions in Parallel Port Mode (Sorted by Pin Name, DS21348T Pin Numbering).....14

Table 2-6. Pin Descriptions in Serial Port Mode (Sorted By Pin Name, DS21348T Pin Numbering) .......16

Table 2-7. Pin Descriptions in Hardware Mode (Sorted By Pin Name, DS21348T Pin Numbering) ........ 18

Table 2-8. Loopback Control in Hardware Mode......................................................................................21

Table 2-9. Transmit Data Control in Hardware Mode...............................................................................21

Table 2-10. Receive Sensitivity Settings ..................................................................................................21

Table 2-11. Monitor Gain Settings............................................................................................................21

Table 2-12. Internal Rx Termination Select ..............................................................................................21

Table 2-13. MCLK Selection.....................................................................................................................22

Table 3-1. Register Map ...........................................................................................................................25

Table 4-1. MCLK Selection.......................................................................................................................30

Table 4-2. Receive Equalizer Sensitivity Settings ....................................................................................32

Table 4-3. Backplane Clock Select...........................................................................................................34

Table 4-4. Monitor Gain Settings..............................................................................................................34

Table 4-5. Internal Rx Termination Select ................................................................................................34

Table 5-1. Received Alarm Criteria ..........................................................................................................36

Table 5-2. Receive Level Indication .........................................................................................................40

Table 6-1. Transmit Code Length.............................................................................................................41

Table 6-2. Receive Code Length..............................................................................................................42

Table 6-3. Definition of Received Errors...................................................................................................47

Table 6-4. Function of ECRS Bits and RNEG Pin ....................................................................................48

Table 7-1. Line Build-Out Select for E1 in Register CCR4 (ETS = 0)....................................................... 51

Table 7-2. Line Build-Out Select for T1 in Register CCR4 (ETS = 1)....................................................... 51

Table 7-3. Transformer Specifications for 3.3V Operation .......................................................................51

Table 8-1. DS21Q348 Pin Assignment..................................................................................................... 58

Table 9-1. Recommended DC Operating Conditions ...............................................................................62

Table 9-2. Capacitance ............................................................................................................................62

Table 9-3. DC Characteristics ..................................................................................................................62

Table 10-1. Thermal Characteristics—DS21Q348 CSBGA Package.......................................................63

Table 10-2. Theta-JA (θJA) vs. Airflow.......................................................................................................63

Table 11-1. AC Characteristics—Multiplexed Parallel Port (BIS1 = 0, BIS0 = 0) ..................................... 64

Table 11-2. AC Characteristics—Nonmultiplexed Parallel Port (BIS1 = 0, BIS0 = 1)...............................67

Table 11-3. AC Characteristics—Serial Port (BIS1 = 1, BIS0 = 0) ...........................................................70

Table 11-4. AC Characteristics—Receive Side........................................................................................71

Table 11-5. AC Characteristics—Transmit Side.......................................................................................72

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DS21348/DS21Q348

1. INTRODUCTION

The analog AMI/HDB3 waveform off of the E1 line or the AMI/B8ZS waveform off of the T1 line is transformer coupled into the RTIP and RRING pins of the DS21348. The user has the option to use internal termination, software selectable for 75Ω/100Ω/120Ω applications, or external termination. The device recovers clock and data from the analog signal and passes it through the jitter attenuation MUX outputting the received line clock at RCLK and bipolar or NRZ data at RPOS and RNEG. The DS21348 contains an active filter that reconstructs the analog received signal for the nonlinear losses that occur in transmission. The receive circuitry is also configurable for various monitor applications. The device has a usable receive sensitivity of 0dB to -43dB for E1 and 0dB to -36dB for T1, which allows the device to operate on 0.63mm (22AWG) cables up to 2.5km (E1) and 6k feet (T1) in length. Data input at TPOS and TNEG is sent via the jitter attenuation mux to the waveshaping circuitry and line driver. The DS21348 will drive the E1 or T1 line from the TTIP and TRING pins via a coupling transformer. The line driver can handle both CEPT 30/ISDN-PRI lines for E1 and long-haul (CSU) or short-haul (DSX-1) lines for T1.

1.1 Document Revision History

REVISION DESCRIPTION

011801 Data sheet revised for 3.3V only.

092101

101104 Corrected typos and removed all instances of 5V operation.

113004

011206 Added lead-free packages to Ordering Information table on page 1.

Added supply current measurements Added thermal characteristics of quad package

Updated the storage and soldering temperature specs in the Absolute Maximum Ratings section.

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Figure 1-1. DS21348 Block Diagram

DS21348/DS21Q348

RRING

RTIP

TRING

TTIP

BIS1

BIS0

VSS

Power Connections

VSM

VDD

JACLK

VCO / PLL

Termination

Optional

nalog Loopback

MUX (the Serial, Parallel, and Hardware Interfaces share device pins)

Filte

Unframed Insertion

Line Drivers

Peak Detect

ll Ones

CSU Filters

Recovery

Clock / Data

Remote Loopback (Dual Mode)

Wave Shaping

Jitter

ttenuato

MUX

Local Loopback

Jitter Attenuation

(can be placed in either transmit or receive path)

MCLK

2.048MHz to

1.544MHz PLL

Remote Loopback

16.384MHz or

8.192MHz or

4.096MHz or

2.048MHz Synthesizer

M U

See Figure 3-2

MUX RCL/LOTC

See Figure 1-3

Control and Test Port

(routed to all blocks)

BPCLK

RPOS

RCLK

RNEG

PBEO

TPOS TCLK

TNEG

RST

TEST

Serial Interface

SDI

SCLK

DS21348

Hardware

Interface

D0 to D7 /

D0 to AD7

Control and

Interrupt

Parallel Interface

SDO

PBTS

R(R/W)

LE(AS)

D(DS)

0 to A4

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Figure 1-2. Receive Logic

DS21348/DS21Q348

From Remote Loopback

Routed to All Blocks

4 or 8 Zero Detect

16 Zero Detect

RIR1.7 RIR1.6

Clock Invert

CCR2.0

CCR2.3

CCR6.2/ CCR6.0/ CCR6.1

B8ZS/HDB3 Decoder

RIR1.5

All Ones Detector

NRZ Data

BPV/CV/EXZ

Loop Code Detector

SR.6 SR.7SR.4 RIR1.3

PRBS Detector

SR.0

CCR1.4

mux

16-Bit Error Counter (ECR)

RCLK

RPOS

mux

RNEG

CCR1.6

PBEO

CCR6.0

rx bd

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Figure 1-3. Transmit Logic

DS21348/DS21Q348

To Remote Loopback

CCR3.1

BPV Insert

Routed to All Blocks

CCR1.6

OR Gate

mux

CCR3.4

PRBS Generator

Loop Code Generator

JACLK (derived from MCLK)

OR Gate

Clock Invert

CCR2.1

TPOS

TNEG

TCLK

CCR3.3

CCR2.2

CCR3.0

mux

B8ZS/ HDB3 Coder

RCLK

mux

OR Gate

Logic Error Insert

CCR1.1

CCR1.2

AND Gate

CCR1.0

To LOTC Output Pin

Loss Of Transmit Clock Detect

SR.5

tx bd

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DS21348/DS21Q348

2. PIN DESCRIPTION

The DS21348 can be controlled in a parallel port mode, serial port mode, or hardware mode (Table 2-2,

Table 2-3, and Table 2-4).

Table 2-1. Bus Interface Selection

BIS1 BIS0 PBTS MODE

0 0 0 Muxed Intel 0 0 1 Muxed Motorola 0 1 0 Nonmuxed Intel 0 1 1 Nonmuxed Motorola 1 0 — Serial Port 1 1 — Hardware

Table 2-2. Pin Assignment in Parallel Port Mode

DS21348T DS21348G

C3 I

I/O

2 C2 I 3 B1 I

PARALLEL

PORT MODE

RD (DS)

WR (R/W)

4 D2 I ALE (AS) 5 C1 I NA 6 D3 I NA 7 D1 I/O A4 8 E1 I A3

9 F2 I A2 10 F1 I A1 11 G1 I A0 12 E3 I/O D7/AD7 13 F3 I/O D6/AD6 14 G2 I/O D5/AD5 15 F4 I/O D4/AD4 16 G3 I/O D3/AD3 17 E4 I/O D2/AD2 18 G4 I/O D1/AD1 19 F5 I/O D0/AD0 20 G5 I VSM 21 F6 — VDD 22 G6 — VSS 23 E5 I/O

INT

24 E6 O PBEO 25 F7 O RCL/LOTC 26 D6 I TEST 27 D5 I RTIP

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DS21348T DS21348G

28 D7 I RRING 29 C6 I 30 C7 I MCLK 31 B6 O BPCLK 32 B7 I BIS0 33 A7 I BIS1 34 C5 O TTIP 35 B5 — VSS 36 A6 — VDD 37 B4 O TRING 38 C4 O RPOS 39 A4 O RNEG 40 B3 O RCLK 41 A3 I TPOS 42 B2 I TNEG 43 A2 I TCLK 44 A1 I PBTS

I/O

DS21348/DS21Q348

PARALLEL

PORT MODE

HRST

Table 2-3. Pin Assignment in Serial Port Mode

DS21348T DS21348G

C3 I

I/O

2 C2 I NA

3 B1 I NA

4 D2 I NA

5 C1 I SCLK

6 D3 I SDI

7 D1 I/O SDO

8 E1 I ICES

9 F2 I OCES 10 F1 I NA 11 G1 I NA 12 E3 I/O NA 13 F3 I/O NA 14 G2 I/O NA 15 F4 I/O NA 16 G3 I/O NA 17 E4 I/O NA 18 G4 I/O NA 19 F5 I/O NA 20 G5 I VSM 21 F6 — VDD 22 G6 — VSS

SERIAL

PORT MODE

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DS21348T DS21348G

I/O

23 E5 I/O

SERIAL

PORT MODE

INT

24 E6 O PBEO 25 F7 O RCL/LOTC 26 D6 I TEST 27 D5 I RTIP 28 D7 I RRING 29 C6 I

HRST

30 C7 I MCLK 31 B6 O BPCLK 32 B7 I BIS0 33 A7 I BIS1 34 C5 O TTIP 35 B5 — VSS 36 A6 — VDD 37 B4 O TRING 38 C4 O RPOS 39 A4 O RNEG 40 B3 O RCLK 41 A3 I TPOS 42 B2 I TNEG 43 A2 I TCLK 44 A1 I NA

DS21348/DS21Q348

Table 2-4. Pin Assignment in Hardware Mode

I/O

DS21348T DS21348G

C3 I EGL 2 C2 I ETS 3 B1 I NRZE 4 D2 I SCLKE 5 C1 I L2 6 D3 I L1 7 D1 I/O L0 8 E1 I DJA 9 F2 I JAMUX

10 F1 I JAS 11 G1 I HBE 12 E3 I/O CES 13 F3 I/O TPD 14 G2 I/O TX0 15 F4 I/O TX1 16 G3 I/O LOOP0

HARDWARE

MODE

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DS21348T DS21348G

17 E4 I/O LOOP1 18 G4 I/O MM0 19 F5 I/O MM1 20 G5 I VSM 21 F6 — VDD 22 G6 — VSS 23 E5 I/O RT1 24 E6 O PBEO 25 F7 O RCL 26 D6 I TEST 27 D5 I RTIP 28 D7 I RRING 29 C6 I 30 C7 I MCLK 31 B6 O BPCLK 32 B7 I BIS0 33 A7 I BIS1 34 C5 O TTIP 35 B5 — VSS 36 A6 — VDD 37 B4 O TRING 38 C4 O RPOS 39 A4 O RNEG 40 B3 O RCLK 41 A3 I TPOS 42 B2 I TNEG 43 A2 I TCLK 44 A1 I RT0

I/O

DS21348/DS21Q348

HARDWARE

MODE

HRST

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DS21348/DS21Q348

2.1 Pin Descriptions Table 2-5. Pin Descriptions in Parallel Port Mode (Sorted by Pin Name,

DS21348T Pin Numbering)

NAME PIN I/O FUNCTION

Address Bus. In nonmultiplexed bus operation (BIS1 = 0, BIS0 =

A0 to A4 11 to 7 I

ALE (AS) 4 I

BIS0/BIS1 32/33 I

BPCLK 31 O

D0/AD0 to

D7/AD7

HRST

INT

1 I

19 to 12 I/O

29 I

23 O

MCLK 30 I

N/A — I Not Assigned. Should be tied low.

PBEO 24 O

1), serves as the address bus. In multiplexed bus operation (BIS1 = 0, BIS0 = 0), these pins are not used and should be tied low. Address Latch Enable (Address Strobe). When using the parallel port (BIS1 = 0) in multiplexed bus mode (BIS0 = 0), serves to demultiplex the bus on a positive-going edge. In nonmultiplexed bus mode (BIS0 = 1), should be tied low. Bus Interface Select Bits 0 and 1. Used to select bus interface option. See Table 2-1

for details.

Backplane Clock. A 16.384MHz, 8.192MHz, 4.096MHz, or

2.048MHz clock output that is referenced to RCLK selectable via CCR5.7 and CCR5.6. In hardware mode, defaults to 16.384MHz output. Chip Select, Active Low. This active-low signal must be low to read or write to the device. Data Bus/Address/Data Bus. In nonmultiplexed bus operation (BIS1 = 0, BIS0 = 1), serves as the data bus. In multiplexed bus operation (BIS1 = 0, BIS0 = 0), serves as an 8-bit multiplexed address/data bus. Hardware Reset, Active Low. Bringing HRST low resets the DS21348, setting all control bits to their default state of all zeros. Interrupt, Active Low. Flags host controller during conditions and change of conditions defined in the Status Register. Active low, open drain output. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. Use of a T1 1.544MHz clock source is optional.

PRBS Bit Error Output. The receiver will constantly search for a 215-1 or a 220-1 PRBS depending on the ETS bit setting (CCR1.7). Remains high if out of synchronization with the PRBS pattern. Goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization will cause a positive going pulse (with same period as E1 or T1 clock) synchronous with RCLK. PRBS bit errors can also be reported to the ECR1 and ECR2 registers by setting CCR6.2 to a logic 1.

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NAME PIN I/O FUNCTION

Parallel Bus Type Select. When using the parallel port (BIS1 = 0),

set high to select Motorola bus timing, set low to select Intel bus

PBTS 44 I

timing. This pin controls the function of the RD (DS), ALE (AS), and WR (R/W) pins. If PBTS = 1 and BIS1 = 0, then these pins assume the Motorola function listed in parentheses (). In serial port mode, this pin should be tied low.

RCLK 40 O

Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Read Input (Data Strobe), Active Low. DS is active low when in

RD (DS)

2 I

nonmultiplexed, Motorola mode. See the bus timing diagrams in Section 11. Receive Carrier Loss/Loss of Transmit Clock. An output which

RCL/

LOTC

25 O

will toggle high during a receive carrier loss (CCR2.7 = 0) or will toggle high if the TCLK pin has not been toggled for 5 µsec ± 2 µsec (CCR2.7 = 1). CCR2.7 defaults to logic 0 when in hardware

mode. Receive Negative Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with the bipolar data out

RNEG 39 O

of the line interface. Set NRZE (CCR1.6) to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4 for details. Receive Positive Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with bipolar data out of the

RPOS 38 O

line interface. Set NRZE (CCR1.6) to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4 for details.

RTIP/

RRING

27/28 I

Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect via a 1:1 transformer to the line. See Section 5 for details. Transmit Clock. A 2.048MHz or 1.544MHz primary clock. Used to

TCLK 43 I

clock data through the transmit side formatter. Can be sourced internally by MCLK or RCLK. See Common Control Register 1 and

Figure 1-3.

Tri-State Control. Set high to tri-state all outputs and I/O pins

TEST 26 I

(including the parallel control port). Set low for normal operation. Useful in board level testing. Transmit Negative Data. Sampled on the falling edge (CCR2.1 =

TNEG 42 I

0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Positive Data. Sampled on the falling edge (CCR2.1 = 0)

TPOS 41 I

or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line.

DS21348/DS21Q348

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NAME PIN I/O FUNCTION

DS21348/DS21Q348

TTIP/

TRING

34/37 O

Transmit Tip and Ring [TTIP AND TRING]. Analog line driver outputs. These pins connect via a step-up transformer to the line. See Section 5

for details. VDD 21/36 — Positive Supply. 3.3V ±5% VSM 20 I Voltage Supply Mode. Should be low for 3.3V operation.

VSS 22/35 —

WR (R/W)

3 I

Signal Ground Write Input (Read/Write), Active Low. See the bus timing

diagrams in Section 11.

Table 2-6. Pin Descriptions in Serial Port Mode (Sorted By Pin Name, DS21348T Pin Numbering)

NAME PIN I/O FUNCTION

BIS0/BIS1 32/33 I

BPCLK 31 O

HRST

1 I

29 I

ICES 8 I

INT

23 O

MCLK 30 I

NA — I Not Assigned. Should be tied low.

OCES 9 I

PBEO 24 O

Bus Interface Select Bits 0 and 1. Used to select bus interface option. See Table 2-1 for details. Backplane Clock. A 16.384MHz, 8.192MHz, 4.096MHz, or

2.048MHz clock output that is referenced to RCLK selectable via CCR5.7 and CCR5.6. In hardware mode, defaults to 16.384MHz output. Chip Select, Active Low. Active-low signal must be low to read or write to the device. Hardware Reset, Active Low. Bringing HRST low will reset the DS21348 setting all control bits to their default state of all zeros. Input Clock Edge Select. Selects whether the serial port data input (SDI) is sampled on rising (ICES =0) or falling edge (ICES = 1) of SCLK. Interrupt, Active Low. Flags host controller during conditions and change of conditions defined in the Status Register. Active-low, open-drain output. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. Use of a T1 1.544MHz clock source is optional.

Output Clock Edge Select. Selects whether the serial port data output (SDO) is valid on the rising (OCES = 1) or falling edge (OCES = 0) of SCLK. PRBS Bit Error Output. The receiver will constantly search for a

-1 or a 220-1 PRBS depending on the ETS bit setting (CCR1.7). Remains high if out of synchronization with the PRBS pattern. Goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization will cause a positive going pulse (with same period as E1 or T1 clock) synchronous with RCLK. PRBS bit errors can also be reported to the ECR1 and ECR2 registers by setting CCR6.2 to a logic 1.

16 of 76

NAME PIN I/O FUNCTION

DS21348/DS21Q348

RCLK 40 O

Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Receive Carrier Loss/Loss of Transmit Clock. An output which

RCL/LOTC 25 O

will toggle high during a receive carrier loss (CCR2.7 = 0) or will toggle high if the TCLK pin has not been toggled for 5µs ± 2µs

(CCR2.7 = 1). CCR2.7 defaults to logic 0 when in hardware mode. Receive Negative Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with the bipolar data out

RNEG 39 O

RPOS 38 O

RTIP/

RRING

27/28 I

Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect via a 1:1 transformer to the line. See Section 5 for details.

SCLK 5 I Serial Clock. Serial bus clock input.

SDI 6 I

SDO 7 O

Serial Data Input. Sampled on rising edge (ICES = 0) or the falling edge (ICES = 1) of SCLK. Serial Data Output. Valid on the falling edge (OCES = 0) or the rising edge (OCES = 1) of SCLK. Transmit Clock. A 2.048MHz or 1.544MHz primary clock. Used to

TCLK 43 I

clock data through the transmit side formatter. Can be sourced internally by MCLK or RCLK. See Common Control Register 1 and

Figure 1-3

Tri-State Control. Set high to tri-state all outputs and I/O pins

TEST 26 I

(including the parallel control port). Set low for normal operation. Useful in board-level testing. Transmit Negative Data. Sampled on the falling edge (CCR2.1 =

TNEG 42 I

0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Positive Data. Sampled on the falling edge (CCR2.1 = 0)

TPOS 41 I

or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line.

TTIP/TRIN

34/37 O

Transmit Tip and Ring [TTIP and TRING]. Analog line-driver outputs. These pins connect via a step-up transformer to the line. See Section 5 for details.

VDD 21/36 — Positive Supply. 3.3V ±5% VSM 20 I Voltage Supply Mode. Should be tied low for 3.3V operation.

VSS 22/35 —

Signal Ground

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DS21348/DS21Q348

Table 2-7. Pin Descriptions in Hardware Mode (Sorted By Pin Name, DS21348T Pin Numbering)

NAME PIN I/O FUNCTION

BIS0/BIS1 32/33 I

Bus Interface Select Bits 0 and 1. Used to select bus interface option. BIS0 = 1 and BIS1 = 1 selects hardware mode.

BPCLK 31 O Backplane Clock. 16.384MHz output.

Receive and Transmit Clock Edge Select. Selects which RCLK edge to update RPOS and RNEG and which TCLK edge to sample TPOS and TNEG.

CES 12 I

0 = update RNEG/RPOS on rising edge of RCLK; sample TPOS/TNEG on falling edge of TCLK 1 = update RNEG/RPOS on falling edge of RCLK; sample TPOS/TNEG on rising edge of TCLK

Disable Jitter Attenuator.

DJA 8 I

0 = jitter attenuator enabled 1 = jitter attenuator disabled Receive Equalizer Gain Limit. This pin controls the sensitivity of the receive equalizer.

EGL E1 (ETS = 0)

EGL 1 I

0 = -12dB (short haul) 1 = -43dB (long haul)

EGL T1 (ETS = 1)

0 = -36dB (long haul) 1 = -30dB (limited long haul) E1/T1 Select.

ETS 2 I

0 = E1 1 = T1 Receive and Transmit HDB3/B8ZS Enable

HBE 11 I

0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1)

HRST

29 I

JAMUX 9 I

JAS 10 I

L0/L1/L2 7/6/5 I

LOOP0/

LOOP1

16/17 I

Hardware Reset. Bringing HRST low will reset the DS21348.

Jitter Attenuator Mux. Controls the source for JACLK.

See Figure 1-1 and Table 2-13.

E1 (ETS = 0) JAMUX

MCLK = 2.048MHz 0

T1 (ETS = 1)

MCLK = 2.048MHz 1 MCLK = 1.544MHz 0

Jitter Attenuator Select

0 = place the jitter attenuator on the receive side 1 = place the jitter attenuator on the transmit side Transmit LIU Waveshape Select Bits 0 and 1 [H/W Mode]. These inputs determine the waveshape of the transmitter (Table 7-1 and Table 7-2

. Loopback Select Bits 0 and 1 [H/W Mode]. These inputs determine the active loopback mode (if any). See Table 2-8.

18 of 76

NAME PIN I/O FUNCTION

Master Clock. A 2.048MHz (±50ppm) clock source with TTL

levels is applied at this pin. This clock is used internally for both

MCLK 30 I

clock/data recovery and for jitter attenuation. Use of a T1 1.544MHz clock source is optional. G.703 requires an accuracy of ±50ppm for

both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces.

MM0/MM1 18/19 I

Monitor Mode Select Bits 0 and 1 [H/W Mode]. These inputs determine if the receive equalizer is in a monitor mode (Table 2-11).

NA — I Not Assigned. Should be tied low.

NRZ Enable [H/W Mode]

NRZE 3 I

0 = Bipolar data at RPOS/RNEG and TPOS/TNEG 1 = NRZ data at RPOS and TPOS or TNEG; RNEG outputs a positive going pulse when device receives a BPV, CV, or EXZ. PRBS Bit Error Output. The receiver will constantly search for a QRSS (T1) or a 215-1 (E1) PRBS depending whether T1 or E1 mode is selected. Remains high if out of synchronization with the

PBEO 24 O

PRBS pattern. Goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization will cause a positive going pulse (with same period as E1 or T1 clock) synchronous with RCLK.

RCLK 40 O

RCL 25 O

Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Receive Carrier Loss. An output which will toggle high during a receive carrier loss. Receive Negative Data. Updated on the rising edge (CES = 0) or the falling edge (CES = 1) of RCLK with the bipolar data out of the

RNEG 39 O

line interface. Set NRZE to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4

for details. Receive Positive Data. Updated on the rising edge (CES = 0) or the falling edge (CES = 1) of RCLK with bipolar data out of the line

RPOS 38 O

interface. Set NRZE pin to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See

RT0/RT1 44/23 I

RTIP/

RRING

27/28 I

section 6.4 Receive LIU Termination Select Bits 0 and 1 [H/W Mode]. These inputs determine the receive termination. See Table 2-12. Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect via a 1:1 transformer to the line. See Section 5 for details.

for details.

Receive and Transmit Synchronization Clock Enable

SCLKE 4 I

0 = disable 2.048MHz synchronization transmit and receive mode 1 = enable 2.048 Hz synchronization transmit and receive mode

TCLK 43 I

Transmit Clock. A 2.048MHz or 1.544MHz primary clock. Used to clock data through the transmit side formatter.

19 of 76

DS21348/DS21Q348

NAME PIN I/O FUNCTION

Tri-State Control. Set high to tri-state all outputs and I/O pins

TEST 26 I

(including the parallel control port). Set low for normal operation. Useful in board-level testing. Transmit Negative Data. Sampled on the falling edge (CES = 0) or

TNEG 42 I

the rising edge (CES = 1) of TCLK for data to be transmitted out onto the line.

Transmit Power-Down

TPD 13 I

0 = normal transmitter operation 1 = powers down the transmitter and tri-states the TTIP and TRING pins Transmit Positive Data. Sampled on the falling edge (CES = 0) or

TPOS 41 I

the rising edge (CES = 1) of TCLK for data to be transmitted out onto the line. Transmit Tip and Ring [TTIP and TRING]. Analog line driver

TTIP/TRING 34/37 O

outputs. These pins connect via a step-up transformer to the line. See Section 5 for details.

TX0/TX1 14/15 I

Transmit Data Source Select Bits 0 and 1 [H/W Mode]. These inputs determine the source of the transmit data. See Table 2-9.

VDD 21/36 — Positive Supply. 3.3V ±5% VSM 20 I Voltage Supply Mode. Should be tied low for 3.3V operation.

VSS 22/35 —

Signal Ground

Note: G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces.

20 of 76

Table 2-8. Loopback Control in Hardware Mode

DS21348/DS21Q348

LOOPBACK SYMBOL

CONTROL

BIT

LOOP1 LOOP0

Remote Loopback RLB CCR6.6 1 1

Local Loopback LLB CCR6.7 1 0

Analog Loopback ALB CCR6.4 0 1

No Loopback — — 0 0

Table 2-9. Transmit Data Control in Hardware Mode

TRANSMIT DATA SYMBOL

Transmit Unframed

All Ones

Transmit Alternating

Ones and Zeros Transmit PRBS

TUA1 CCR3.7 1 1

TAOZ CCR3.5 1 0

TPRBSE

TPOS and TNEG — — 0 0

CONTROL

BIT

CCR3.4

TX1 TX0

0 1

Table 2-10. Receive Sensitivity Settings

EGL

(CCR4.4)

0 0 (E1) -12dB (short haul) 1 0 (E1) -43dB (long haul) 1 1 (T1) -30dB (limited long haul) 0 1 (T1) -36dB (long haul)

ETS

(CCR1.7)

RECEIVE SENSITIVITY

Table 2-11. Monitor Gain Settings

MM1

(CCR5.5)

0 0 Normal operation (no boost) 0 1 20 1 0 26 1 1 32

MM0

(CCR5.4)

INTERNAL LINEAR

GAIN BOOST (dB)

Table 2-12. Internal Rx Termination Select

RT1

(CCR5.1)

0 0 Internal receive-side termination disabled 0 1 1 0 1 1

RT0

(CCR5.0)

INTERNAL RECEIVE

TERMINATION CONFIGURATION

Internal receive-side 120Ω enabled Internal receive-side 100Ω enabled Internal receive-side 75Ω enabled

21 of 76

Table 2-13. MCLK Selection

DS21348/DS21Q348

MCLK

(MHz)

JAMUX

(CCR1.3)

ETS

(CCR1.7)

2.048 0 0

2.048 1 1

1.544 0 1

Figure 2-1. Parallel Port Mode Pinout (BIS1 = 0, BIS0 = 1 or 0) (TQFP Package)

1 2 RD (DS)

3 WR (R/ 4 ALE (AS) 5 NA 6 NA 7 A4 8 A3 9 A2 10 A1 11 A0

44 PBTS

42 TNEG

43 TCLK

)

40 RCLK

41 TPOS

DS21348

Parallel Port

Operation

(NOTE: TIE ALL NA PINS LOW)

39 RNEG

38 RPOS

37 TRING

D0/D0 19 AD1/D1 18 AD2/D2 17 AD3/D3 16 AD4/D4 15 AD5/D5 14 AD6/D6 13 AD7/D7 12

36 VDD

VSM 20

34 TTIP

35 VSS

RCL/LOTC 25

VDD 21

VSS 22

BIS1 33

BIS0 32

BPCLK 31

MCLK 30

RST 29

RRING 28

RTIP 27

TEST 26

PBEO 24

NT 23

tie low

TIE LOW (MUX) OR HIGH (NONMUX)

22 of 76

TIE LOW

DS21348/DS21Q348

Figure 2-2. Serial Port Mode Pinout (BIS1 = 1, BIS0 = 0) (TQFP Package)

TIE LOW

2 NA 3 NA 4 NA 5 SCLK 6 SDI 7 SDO 8 ICES 9 OCES 10 NA 11 NA

44 PBTS

NA 12

40 RCLK

41 TPOS

42 TNEG

43 TCLK

DS21348

Serial Port

Operation

(NOTE: TIE ALL NA PINS LOW)

NA 16

NA 15

NA 14

NA 13

39 RNEG

NA 17

38 RPOS

NA 18

37 TRING

NA 19

36 VDD

35 VSS

VSM 20

VDD 21

TIE LOW

34 TT IP

BIS1 33

BIS0 32

BPCLK 31

MCLK 30

RST 29

RRING 28

RTIP 27

TEST 26

RCL/LOTC 25

PBEO 24

NT 23

VSS 22

TIE HIGH TIE LOW

23 of 76

DS21348/DS21Q348

Figure 2-3. Hardware Mode Pinout (BIS1 = 1, BIS0 = 1) (TQFP Package)

44 RT0

43 TCL

42 TNEG

41 TPOS

40 RCL

39 RNEG

38 RPOS

1 EGL

2 ETS

3 NRZE

4 SCLKE

5 L2

6 L1

7 L0

8 DJ

9 JAMUX

10 JAS

11 HBE

DS21348 Hardware Operation

LOOP1 17

CES 12

TPD 13

TX0 14

LOOP0 16

TX1 15

MM0 18

36 VDD

37 TRING

MM1 19

VSM 20

TIE LOW

35 VSS

VDD 21

34 TTIP

BIS1 33

BIS0 32

BPCLK 31

MCLK 30

RST 29

RRING 28

RTIP 27

TEST 26

RCL 25

PBEO 24

RT1 23

VSS 22

TIE HIGH TIE HIGH

24 of 76

DS21348/DS21Q348

3. HARDWARE MODE

In hardware mode (BIS1 = 1, BIS0 = 1), pins 1–19, 23, 25, 31, and 44 are redefined to be used for initializing the DS21348. BPCLK (pin 31) defaults to a 16.384MHz output when in hardware mode. The RCL/LOTC (pin 25) is designated to RCL when in hardware mode. JABDS (CCR4.2) defaults to logic 0. The RHBE (CCR2.3) and THBE (CCR2.2) control bits are combined and controlled by HBE at pin 11 while the RSCLKE (CCR5.3) and TSCLKE (CCR5.2) bits are combined and controlled by SCLKE at pin 4. TCES (CCR2.1) and RCES (CCR2.0) are combined and controlled by CES at pin 12. The transmitter functions are combined and controlled by TX1 (pin 15) and TX0 (pin 14). The loopback functions are controlled by LOOP1 (pin 17) and LOOP0 (pin 16). All other control bits default to the logic 0 setting.

3.1 Register Map Table 3-1. Register Map

SERIAL PORT

NAME REGISTER R/W

PARALLEL

PORT MODE

MODE

(Notes 2 to 5)

(msb) (lsb)

CCR1 Common Control Register 1 R/W 00h B000 000A CCR2 Common Control Register 2 R/W 01h B000 001A CCR3 Common Control Register 3 R/W 02h B000 010A CCR4 Common Control Register 4 R/W 03h B000 011A CCR5 Common Control Register 5 R/W 04h B000 100A CCR6 Common Control Register 6 R/W 05h B000 101A

SR Status Register R 06h B000 110A

IMR Interrupt Mask Register R/W 07h B000 111A RIR1 Receive Information Register 1 R 08h B001 000A RIR2 Receive Information Register 2 R 09h B001 001A

IBCC In-Band Code Control Register R/W 0Ah B001 010A TCD1 Transmit Code Definition Register 1 R/W 0Bh B001 011A TCD2 Transmit Code Definition Register 2 R/W 0Ch B001 100A

RUPCD1 Receive Up Code Definition Register 1 R/W 0Dh B001 101A

RUPCD2 Receive Up Code Definition Register 2 R/W 0Eh B001 110A RDNCD1 Receive Down Code Definition Register 1 R/W 0Fh B001 111A RDNCD2 Receive Down Code Definition Register 2 R/W 10h B010 000A

ECR1 Error Count Register 1 R 11h B010 001A

ECR2 Error Count Register 2 R 12h B010 010A TEST1 Test 1 R/W 13h B010 011A TEST2 Test 2 R/W 14h B010 100A TEST3 Test 3 R/W 15h B010 101A

— — — (Note 1) —

Note 1:

Note 2:

Note 3:

Note 4:

Note 5:

In the Serial Port Mode, the LSB is on the right hand side.

In the Serial Port Mode, data is read and written LSB first.

In the Serial Port Mode, the A bit (the LSB) determines whether the access is a read (A = 1) or a write (A = 0).

In the Serial Port Mode, the B bit (the MSB) determines whether the access is a burst access (B = 1) or a single register access (B = 0).

25 of 76

DS21348/DS21Q348

3.2 Parallel Port Operation

When using the parallel interface on the DS21348 (BIS1 = 0) the user has the option for either multiplexed bus operation (BIS1 = 0, BIS0 = 0) or non-multiplexed bus operation (BIS1 = 0, BIS0 = 1). The DS21348 can operate with either Intel or Motorola bus timing configurations. If the PBTS pin is tied low, Intel timing will be selected; if tied high, Motorola timing will be selected. All Motorola bus signals are listed in parentheses (). See the timing diagrams in Section 11 for more details.

3.3 Serial Port Operation

Setting BIS1 = 1 and BIS0 = 0 enables the serial bus interface on the DS21348. Port read/write timing is unrelated to the system transmit and receive timing, allowing asynchronous reads or writes by the host. See Section 11 for the AC timing of the serial port. All serial port accesses are LSB first. See Figure 3-1,

Figure 3-2, Figure 3-3, and Figure 3-4 for more details.

Reading or writing to the internal registers requires writing one address/command byte prior to transferring register data. The first bit written (LSB) of the address/command byte specifies whether the access is a read (1) or a write (0). The next 5 bits identify the register address. Bit 7 is reserved and must be set to 0 for proper operation.

The last bit (MSB) of the address/command byte is the burst mode bit. When the burst bit is enabled (B = 1) and a READ operation is performed, addresses 0 through 15h are read sequentially, starting at address 0h. And when the burst bit is enabled and a WRITE operation is performed, addresses 0 through 16h are written sequentially, starting at address 0h. Burst operation is stopped once address 15h is read. See Figure 3-5 and Figure 3-6 for more details.

All data transfers are initiated by driving the CS input low. When Input Clock-Edge Select (ICES) is low, input data is latched on the rising edge of SCLK and when ICES is high, input data is latched on the falling edge of SCLK. When Output Clock-Edge Select (OCES) is low, data is output on the falling edge of SCLK and when OCES is high, data is output on the rising edge of SCLK. Data is held until the next falling or rising edge. All data transfers are terminated if the CS input transitions high. Port control logic is disabled and SDO is tri-stated when CS is high.

26 of 76

DS21348/DS21Q348

A0A1A2A32A

A0A1A2A3A

Figure 3-1. Serial Port Operation for Read Access (R = 1) Mode 1

ICES = 1 (sample SDI on the falling edge of SCLK) OCES = 1 (update SDO on rising edge of SCLK)

SCL

SDI

123456 78910111213141516

(lsb) (msb)

READ ACCESS ENABLED

SDO

40B

D1 D2 D3 D4 D5 D6

(lsb)

Figure 3-2. Serial Port Operation for Read Access Mode 2

ICES = 1 (sample SDI on the falling edge of SCLK) OCES = 0 (update SDO on falling edge of SCLK)

SCL

SDI

SDO

1234 5678 910111213141516

(lsb) (msb)

40 B

D1 D2 D3 D4 D5 D6

(lsb)

(msb)

Figure 3-3. Serial Port Operation for Read Access Mode 3

ICES = 0 (sample SDI on the rising edge of SCLK) OCES = 0 (update SDO on falling edge of SCLK)

SCL

SDI

SDO

123456 78910111213141516

(lsb) (msb)

40 B

D1 D2 D3 D4 D5 D6

(lsb)

27 of 76

(msb)

DS21348/DS21Q348

A0A1A2A

A0A1A2A3A

Figure 3-4. Serial Port Operation for Read Access Mode 4

ICES = 0 (sample SDI on the rising edge of SCLK) OCES = 1 (update SDO on rising edge of SCLK)

SCL

SDI

SDO

1234 5678 910111213141516

(lsb) (msb)

3A5A4

D1 D2 D3 D4 D5 D6 D0 D7

(lsb) (msb)

Figure 3-5. Serial Port Operation for Write Access (R = 0) Modes 1 and 2

ICES = 1 (sample SDI on the falling edge of SCLK)

123456 78910111213141516SCL

SDI

(lsb)

WRITE ACCESS ENABLED

SDO

40B

(msb)

D0 D6

D1 D2 D3 D4 D5 D7

(lsb) (msb)

Figure 3-6. Serial Port Operation for Write Access (R = 0) Modes 3 and 4

ICES = 0 (sample SDI on the rising edge of SCLK)

12345678910111213141516SCL

SDI

(lsb)

WRITE ACCESS ENABLED

SDO

40B

D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0D0

D0D0D0D0

D0 D6

D1 D2 D3 D4 D5 D7

(msb)

(lsb) (msb)

28 of 76

4. CONTROL REGISTERS

CCR1 (00H): COMMON CONTROL REGISTER 1

DS21348/DS21Q348

(MSB)

(LSB)

ETS NRZE RCLA ECUE JAMUX TTOJ TTOR LOTCMC

SYMBOL POSITION DESCRIPTION

ETS CCR1.7

E1/T1 Select. 0 = E1 1 = T1

NRZE CCR1.6

NRZ Enable. 0 = Bipolar data at RPOS/RNEG and TPOS/TNEG 1 = NRZ data at RPOS and TPOS or TNEG; RNEG outputs a positive going pulse when device receives a BPV, CV, or EXZ. See Figure 1-2 and Figure 1-3.

RCLA CCR1.5

Receive Carrier Loss Alternate Criteria. 0 = RCL declared upon 255 (E1) or 192 (T1) consecutive zeros 1 = RCL declared upon 2048 (E1) or 1544 (T1) consecutive zeros

ECUE CCR1.4 Error Counter Update Enable. A 0 to 1 transition forces the next clock

cycle to load the error counter registers with the latest counts and reset the counters. The user must wait a minimum of two clocks cycles (976ns for E1 and 1296ns for T1) before reading the error count registers to allow for a proper update. See Section 4 and Figure 1-2 for details.

JAMUX CCR1.3 Jitter Attenuator MUX. Controls the source for JACLK (Figure 1-1).

0 = JACLK sourced from MCLK (2.048MHz or 1.544MHz at MCLK) 1 = JACLK sourced from internal PLL (2.048MHz at MCLK)

TTOJ CCR1.2 TCLK to JACLK. Internally connects TCLK to JACLK (Figure 1-3).

0 = disabled 1 = enabled

TTOR CCR1.1 TCLK to RCLK. Internally connects TCLK to RCLK (Figure 1-3

). 0 = disabled 1 = enabled

LOTCMC CCR1.0 Loss Of Transmit Clock Mux Control. Determines whether the

transmit logic should switch to JACLK if the TCLK input should fail to transition (Figure 1-3

). 0 = do not switch to JACLK if TCLK stops 1 = switch to JACLK if TCLK stops

29 of 76

Table 4-1. MCLK Selection

DS21348/DS21Q348

MCLK

(MHz)

JAMUX

(CCR1.3)

ETS

(CCR1.7)

2.048 0 0

2.048 1 1

1.544 0 1

CCR2 (01H): COMMON CONTROL REGISTER 2

(MSB)

P25S n/a SCLD CLDS RHBE THBE TCES RCES

SYMBOL POSITION DESCRIPTION

P25S CCR2.7 Pin 25 Select. Forced to logic 0 in hardware mode.

- CCR2.6

SCLD CCR2.5 Short Circuit Limit Disable (ETS = 0). Controls the 50 mA (rms)

CLDS CCR2.4 Custom Line Driver Select. Setting this bit to a one will redefine the

RHBE CCR2.3 Receive HDB3/B8ZS Enable. See Figure 1-2

THBE CCR2.2 Transmit HDB3/B8ZS Enable. See Figure 1-3

TCES CCR2.1 Transmit Clock Edge Select. Selects which TCLK edge to sample TPOS

RCES CCR2.0 Receive Clock Edge Select. Selects which RCLK edge to update RPOS

(LSB)

0 = toggles high during a Receive Carrier Loss condition 1 = toggles high if TCLK does not transition for at least 5µs Not Assigned. Should be set to zero when written to.

current limiter. 0 = enable 50 mA current limiter

1 = DISABLE 50 MA CURRENT LIMITER

operation of the transmit line driver. When this bit is set to a one and CCR4.5 = CCR4.6 = CCR4.7 = 0, then the device will generate a square wave at the TTIP and TRING outputs instead of a normal waveform. When this bit is set to a one and CCR4.5 = CCR4.6 = CCR4.7 ≠ 0, then the device will force TTIP and TRING outputs to become open drain drivers instead of their normal push-pull operation. This bit should be set to zero for normal operation of the device. Contact the factory for more details on how to use this bit.

. 0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1)

and TNEG. See Figure 1-3

. 0 = sample TPOS and TNEG on falling edge of TCLK 1 = sample TPOS and TNEG on rising edge of TCLK

and RNEG. See Figure 1-2

. 0 = update RPOS and RNEG on rising edge of RCLK 1 = update RPOS and RNEG on falling edge of RCLK

30 of 76

CCR3 (02H): COMMON CONTROL REGISTER 3

DS21348/DS21Q348

(MSB)

(LSB)

TUA1 ATUA1 TAOZ TPRBSE TLCE LIRST IBPV IBE

SYMBOL POSITION DESCRIPTION

TUA1 CCR3.7 Transmit Unframed All Ones. The polarity of this bit is set such that the

device will transmit an all ones pattern on power-up or device reset. This bit must be set to a one to allow the device to transmit data. The transmission of this data pattern is always timed off of the JACLK (See

Figure 1-1).

0 = transmit all ones at TTIP and TRING 1 = transmit data normally

ATUA1 CCR3.6 Automatic Transmit Unframed All Ones. Automatically transmit an

unframed all ones pattern at TTIP and TRING during a receive carrier loss (RCL) condition or receive all ones condition. 0 = disabled 1 = enabled

TAOZ CCR3.5 Transmit Alternate Ones and Zeros. Transmit a …101010… pattern at

TTIP and TRING. The transmission of this data pattern is always timed off of TCLK (Figure 1-1). 0 = disabled 1 = enabled

TPRBSE CCR3.4 Transmit PRBS Enable. Transmit a 215 - 1 (E1) or a 220 - 1 (T1) PRBS at

TTIP and TRING (Figure 1-3). 0 = disabled 1 = enabled

TLCE CCR3.3 Transmit Loop Code Enable. Enables the transmit side to transmit the

loop up code in the Transmit Code Definition registers (TCD1 and TCD2). See Section 4 and Figure 1-3 for details. 0 = disabled 1 = enabled

LIRST CCR3.2 Line Interface Reset. Setting this bit from a zero to a one will initiate an

internal reset that resets the clock recovery state machine and re-centers the jitter attenuator. Normally this bit is only toggled on power-up. Must be cleared and set again for a subsequent reset.

IBPV CCR3.1 Insert BPV. A 0 to 1 transition on this bit will cause a single BiPolar

Violation (BPV) to be inserted into the transmit data stream. Once this bit has been toggled from a 0 to a 1, the device waits for the next occurrence of three consecutive ones to insert the BPV. This bit must be cleared and set again for a subsequent error to be inserted (Figure 1-3).

IBE CCR3.0 Insert Bit Error. A 0 to 1 transition on this bit will cause a single logic

error to be inserted into the transmit data stream. This bit must be cleared and set again for a subsequent error to be inserted (Figure 1-3).

31 of 76

DS21348/DS21Q348

4.1 Device Power-Up and Reset

The DS21348 will reset itself upon power-up setting all writeable registers to 00h and clear the status and information registers. CCR3.7 (TUA1) = 0 results in the LIU transmitting unframed all ones. After the power supplies have settled following power-up, initialize all control registers to the desired settings, then toggle the LIRST bit (CCR3.2). At anytime, the DS21348 can be reset to the default settings by bringing HRST (pin 29) low (level triggered) or by powering down and powering up again.

CCR4 (03H): COMMON CONTROL REGISTER 4

(MSB)

(LSB)

L2 L1 L0 EGL JAS JABDS DJA TPD

SYMBOL POSITION DESCRIPTION

L2 CCR4.7 Line Build Out Select Bit 2. Sets the transmitter build out; see Table 7-1

for E1 and Table 7-2 for T1.

L1 CCR4.6 Line Build Out Select Bit 1. Sets the transmitter build out; see Table 7-1

for E1 and Table 7-2 for T1.

L0 CCR4.5 Line Build Out Select Bit 0. Sets the transmitter build out; see Table 7-1

for E1 and Table 7-2 for T1.

EGL CCR4.4 Receive Equalizer Gain Limit. This bit controls the sensitivity of the

receive equalizer. See Table 4-2.

JAS CCR4.3

Jitter Attenuator Select.

0 = place the jitter attenuator on the receive side 1 = place the jitter attenuator on the transmit side

JABDS CCR4.2

Jitter Attenuator Buffer Depth Select.

0 = 128 bits 1 = 32 bits (use for delay-sensitive applications)

DJA CCR4.1

Disable Jitter Attenuator.

0 = jitter attenuator enabled 1 = jitter attenuator disabled

TPD CCR4.0

Transmit Power-Down.

0 = normal transmitter operation 1 = powers down the transmitter and tri-states the TTIP and TRING pins

Table 4-2. Receive Equalizer Sensitivity Settings

EGL

(CCR4.4)

0 0 (E1) -12dB (short haul) 1 0 (E1) -43dB (long haul) 1 1 (T1) -30dB (limited long haul) 0 1 (T1) -36dB (long haul)

ETS

(CCR1.7)

RECEIVE

SENSITIVITY

32 of 76

CCR5 (04H): COMMON CONTROL REGISTER 5

DS21348/DS21Q348

(MSB)

(LSB)

BPCS1 BPCS0 MM1 MM0 RSCLKE TSCLKE RT1 RT0

SYMBOL POSITION DESCRIPTION

BPCS1 CCR5.7 Backplane Clock Select 1. See Table 4-3 for details.

BPCS0 CCR5.6 Backplane Clock Select 0. See Table 4-3 for details

MM1 CCR5.5 Monitor Mode 1. See Table 4-4.

MM0 CCR5.4 Monitor Mode 0. See Table 4-4.

RSCLKE CCR5.3

Receive Synchronization Clock Enable.

This control bit determines whether the line receiver should handle normal T1/E1 signals or a synchronization signal. E1 mode: 0 = receive normal E1 signal (Section 6 of G.703) 1 = receive 2.048MHz synchronization signal (Section 10 of G.703) T1 mode: 0 = receive normal T1 signal 1 = receive 1.544MHz synchronization signal

TSCLKE CCR5.2

Transmit Synchronization Clock Enable.

This control bit determines whether the transmitter should transmit normal T1/E1 signals or a synchronized signal. E1 mode: 0 = transmit normal E1 signal (Section 6 of G.703) 1 = transmit 2.048MHz synchronization signal (Section 10 of G.703) T1 mode: 0 = transmit normal T1 signal 1 = transmit 1.544MHz synchronization signal

RT1 CCR5.1 Receive Termination 1. See Table 4-5 for details.

RT0 CCR5.0 Receive Termination 0. See Table 4-5 for details.

33 of 76

Table 4-3. Backplane Clock Select

DS21348/DS21Q348

BPCS1

(CCR5.7)

BPCS0

(CCR5.6)

BPCLK

FREQUENCY

0 0 16.384MHz 0 1 8.192MHz 1 0 4.096MHz 1 1 2.048MHz

Table 4-4. Monitor Gain Settings

MM1

(CCR5.5)

0 0

0 1 20dB 1 0 26dB 1 1 32dB

MM0

(CCR5.4)

INTERNAL LINEAR

GAIN BOOST

Normal operation (no boost)

Table 4-5. Internal Rx Termination Select

RT1

(CCR5.1)

0 0 Internal receive-side termination disabled 0 1 1 0 1 1

RT0

(CCR5.0)

INTERNAL RECEIVE

TERMINATION CONFIGURATION

Internal receive-side 120Ω enabled Internal receive-side 100Ω enabled Internal receive-side 75Ω enabled

34 of 76

CCR6 (05H): COMMON CONTROL REGISTER 6

DS21348/DS21Q348

(MSB)

(LSB)

LLB RLB ARLBE ALB RJAB ECRS2 ECRS1 ECRS0

SYMBOL POSITION DESCRIPTION

LLB CCR6.7 Local Loopback. In Local Loopback (LLB), transmit data will be looped back

to the receive path passing through the jitter attenuator if it is enabled. Data in the transmit path will act as normal. See Figure 1-1

and Section 6.2.2 for details. 0 = loopback disabled 1 = loopback enabled

RLB CCR6.6 Remote Loopback. In Remote Loopback (RLB), data output from the

clock/data recovery circuitry will be looped back to the transmit path passing through the jitter attenuator if it is enabled. Data in the receive path will act as normal while data presented at TPOS and TNEG will be ignored. See Figure 1-1

and Section 6.2.1 for details. 0 = loopback disabled 1 = loopback enabled

ARLBE CCR6.5 Automatic Remote Loopback Enable and Reset. When this bit is set high,

the device will automatically go into remote loopback when it detects loop up code programmed into the Receive Loop-Up Code Definition Registers (RUPCD1 and RUPCD2) for a minimum of 5 seconds and it will also set the RIR2.1 status bit. Once in a RLB state, it will remain in this state until it has detected the loop code programmed into the Receive Loop-Down Code Definition Registers (RDNCD1 and RDNCD2) for a minimum of 5 seconds at which point it will force the device out of RLB and clear RIR2.1. The automatic RLB circuitry can be reset by toggling this bit from a 1 to a 0. The action of the automatic remote loopback circuitry is logically ORed with the RLB (CCR6.6) control bit (i.e., either one can cause a RLB to occur).

ALB CCR6.4 Analog Loopback. In Analog Loopback (ALB), signals at TTIP and TRING

will be internally connected to RTIP and RRING. The incoming signals, from the line, at RTIP and RRING will be ignored. The signals at TTIP and TRING will be transmitted as normal. See Figure 1-1

and Section 6.2.3 for more details.

0 = loopback disabled 1 = loopback enabled

RJAB CCR6.3 RCLK Jitter Attenuator Bypass. This control bit allows the receive recovered

clock and data to bypass the jitter attenuation while still allowing the BPCLK output to use the jitter attenuator. See Figure 1-1

and Section 7.3 for details. 0 = disabled 1 = enabled

ECRS2 CCR6.2 Error Count Register Select 2. See Section 6.4 for details.

ECRS1 CCR6.1 Error Count Register Select 1. See Section 6.4 for details.

ECRS0 CCR6.0 Error Count Register Select 0. See Section 6.4 for details.

35 of 76

DS21348/DS21Q348

5. STATUS REGISTERS

There are three registers that contain information on the current real-time status of the device, Status Register (SR) and Receive Information Registers 1 and 2 (RIR1/RIR2). When a particular event has occurred (or is occurring), the appropriate bit in one of these three registers will be set to a one. Some of the bits in SR, RIR1, and RIR2 are latched bits and some are real time bits. The register descriptions below list which status bits are latched and which are real time bits. For latched status bits, when an event or an alarm occurs the bit is set to a one and will remain set until the user reads that bit. The bit will be cleared when it is read and it will not be set again until the event has occurred again. Two of the latched status bits (RUA1 and RCL) will remain set after reading if the alarm is still present.

The user will always precede a read of any of the three status registers with a write. The byte written to the register will inform the DS21348 which bits the user wishes to read and have cleared. The user will write a byte to one of these registers with a one in the bit positions to be read and a zero in the other bit positions. When a one is written to a bit location, that location will be updated with the latest information. When a zero is written to a bit position, that bit position will not be updated and the previous value will be held. A write to the status and information registers will be immediately followed by a read of the same register. The read result should be logically ANDed with the mask byte that was just written and this value should be written back into the same register to insure that bit does indeed clear. This second write step is necessary because the alarms and events in the status registers occur asynchronously with respect to their access via the parallel port. This write-read-write scheme allows an external microcontroller or microprocessor to individually poll certain bits without disturbing the other bits in the register. This operation is key in controlling the DS21348 with higher-order software languages.

The bits in the SR register have the unique ability to initiate a hardware interrupt via the INT output pin. Each of the alarms and events in the SR can be either masked or unmasked from the interrupt pin via the Interrupt Mask Register (IMR). The interrupts caused by the RCL, RUA1, and LOTC bits in SR act differently than the interrupts caused by the other status bits in SR. The RCL, RUA1 and LOTC bits will force the INT pin low whenever they change state (i.e., go active or inactive). The INT pin will be allowed to return high (if no other interrupts are present) when the user reads the alarm bit that caused the interrupt to occur even if the alarm is still present. The other status bits in SR can force the INT pin low when they are set. The INT pin will be allowed to return high (if no other interrupts are present) when the user reads the event bit that caused the interrupt to occur.

Table 5-1. Received Alarm Criteria

ALARM E1/T1 SET CRITERIA CLEAR CRITERIA

RUA1 E1 Less than 2 zeros in two frames (512 bits)

RUA1 T1

RCL

Note 1: Note 2:

Receive carrier loss (RCL) is also known as loss of signal (LOS) or Red Alarm in T1. See CCR1.5 for details.

Over a 3ms window, five or fewer zeros are received 255 (or 2048)

consecutive zeros received

(G.775)

192 (or 1544)2 consecutive zeros are received

More than 2 zeros in two frames (512 bits) Over a 3ms window, six or more zeros are received In 255 bit times, at least 32 ones are received 14 or more ones out of 112 possible bit positions are received starting with the first one received

36 of 76

SR (06H): STATUS REGISTER

DS21348/DS21Q348

(MSB)

(LSB)

LUP LDN LOTC RUA1 RCL TCLE TOCD PRBSD

SYMBOL POSITION DESCRIPTION

LUP

(latched)

LDN

(latched)

SR.7 Loop-Up Code Detected. Set when the loop-up code defined in registers

RUPCD1 and RUPCD2 is being received. See Section 4

for details.

SR.6 Loop-Down Code Detected. Set when the loop-down code defined in

registers RDNCD1 and RDNCD2 is being received. See Section 4

for

details.

LOTC

(real time)

RUA1

(latched)

RCL

(latched)

TCLE

(real time)

TOCD

(real time)

PRBSD

(real time)

SR.5 Loss of Transmit Clock. Set when the TCLK pin has not transitioned for

5µsec (±2µs). Will force the LOTC pin high.

SR.4 Receive Unframed All Ones. Set when an unframed all ones code is

received at RRING and RTIP. See Table 5-1

for details.

SR.3 Receive Carrier Loss. Set when a receive carrier loss condition exists at

RRING and RTIP. See Table 5-1

for details.

SR.2 Transmit Current Limit Exceeded. Set when the 50mA (RMS) current

limiter is activated whether the current limiter is enabled or not.

SR.1 Transmit Open Circuit Detect. Set when the device detects that the TTIP

and TRING outputs are open circuited.

SR.0 PRBS Detect. Set when the receive-side detects a 215 - 1 (E1) or a 220 - 1

(T1) Pseudo-Random Bit Sequence (PRBS).

37 of 76

IMR (07H): INTERRUPT MASK REGISTER

DS21348/DS21Q348

(MSB)

(LSB)

LUP LDN LOTC RUA1 RCL TCLE TOCD PRBSD

SYMBOL POSITION DESCRIPTION

LUP IMR.7

Loop-Up Code Detected.

0 = interrupt masked 1 = interrupt enabled

LDN IMR.6

Loop-Down Code Detected.

0 = interrupt masked 1 = interrupt enabled

LOTC IMR.5

Loss of Transmit Clock.

0 = interrupt masked 1 = interrupt enabled

RUA1 IMR.4

Receive Unframed All Ones.

0 = interrupt masked 1 = interrupt enabled

RCL IMR.3

Receive Carrier Loss.

0 = interrupt masked 1 = interrupt enabled

TCLE IMR.2

Transmit Current Limiter Exceeded.

0 = interrupt masked 1 = interrupt enabled

TOCD IMR.1

Transmit Open Circuit Detect. 0 = interrupt masked 1 = interrupt enabled

PRBSD IMR.0

PRBS Detection. 0 = interrupt masked 1 = interrupt enabled

38 of 76

RIR1 (08H): RECEIVE INFORMATION REGISTER 1

DS21348/DS21Q348

(MSB)

(LSB)

ZD 16ZD HBD RCLC RUA1C JALT n/a n/a

SYMBOL POSITION DESCRIPTION

(latched)

RIR1.7 Zero Detect. Set when a string of at least four (ETS = 0) or eight

(ETS = 1) consecutive zeros (regardless of the length of the string) have been received. Will be cleared when read.

16ZD

(latched)

RIR1.6 Sixteen Zero Detect. Set when at least 16 consecutive zeros

(regardless of the length of the string) have been received. Will be cleared when read.

HBD

(latched)

RIR1.5 HDB3/B8ZS Word Detect. Set when an HDB3 (ETS = 0) or B8ZS

(ETS = 1) code word is detected independent of whether the receive HDB3/B8ZS mode (CCR4.6) is enabled. Will be cleared when read. Useful for automatically setting the line coding.

RCLC

(latched)

RUA1C

(latched)

JALT

(latched)

RIR1.4 Receive Carrier Loss Clear. Set when the RCL alarm has met the

clear criteria defined in Table 5-1. Will be cleared when read.

RIR1.3 Receive Unframed All Ones Clear. Set when the unframed all ones

signal is no longer detected. Will be cleared when read (Table 5-1).

RIR1.2 Jitter Attenuator Limit Trip. Set when the jitter attenuator FIFO

reaches to within 4 bits of its useful limit. Will be cleared when read. Useful for debugging jitter attenuation operation.

N/A RIR1.1 Not Assigned. Could be any value when read.

N/A RIR1.0 Not Assigned. Could be any value when read.

39 of 76

RIR2 (09H): RECEIVE INFORMAION REGISTER 2

DS21348/DS21Q348

(MSB)

(LSB)

RL3 RL2 RL1 RL0 N/A N/A ARLB SEC

SYMBOL POSITION DESCRIPTION

RL3

RIR2.7 Receive Level Bit 3. See Table 5-2.

(real time)

RL2

RIR2.6 Receive Level Bit 2. See Table 5-2.

(real time)

RL1

RIR2.5 Receive Level Bit 1. See Table 5-2.

(real time)

RL0

RIR2.4 Receive Level Bit 0. See Table 5-2.

(real time)

N/A RIR2.3 Not Assigned. Could be any value when read.

N/A RIR2.2 Not Assigned. Could be any value when read.

ARLB

(real time)

RIR2.1 Automatic Remote Loopback Detected. This bit will be set to a one

when the automatic Remote Loopback (RLB) circuitry has detected the presence of a loop up code for 5 seconds. It will remain set until the automatic RLB circuitry has detected the loop down code for 5 seconds. See Section 4 for more details. This bit will be forced low when the automatic RLB circuitry is disabled (CCR6.5 = 0).

SEC

(latched)

RIR2.0 One-Second Timer. This bit will be set to a one on one-second

boundaries as timed by the device based on the RCLK. It will be cleared when read.

Table 5-2. Receive Level Indication

RL3 RL2 RL1 RL0 RECEIVE LEVEL (dB)

0 0 0 0 < -2.5 0 0 0 1 -2.5 to -5.0 0 0 1 0 -5.0 to -7.5 0 0 1 1 -7.5 to -10.0 0 1 0 0 -10.0 to -12.5 0 1 0 1 -12.5 to -15.0 0 1 1 0 -15.0 to -17.5 0 1 1 1 -17.5 to -20.0 1 0 0 0 -20.0 to -22.5 1 0 0 1 -22.5 to -25.0 1 0 1 0 -25.0 to -27.5 1 0 1 1 -27.5 to -30.0 1 1 0 0 -30.0 to -32.5 1 1 0 1 -32.5 to -35.0 1 1 1 0 -35.0 to -37.5 1 1 1 1 > -37.5

40 of 76

DS21348/DS21Q348

6. DIAGNOSTICS

6.1 In-Band Loop Code Generation and Detection

The DS21348 can generate and detect a repeating bit pattern that is from one to eight or sixteen bits in length. To transmit a pattern, the user will load the pattern to be sent into the Transmit Code Definition (TCD1 and TCD2) registers and select the proper length of the pattern by setting the TC0 and TC1 bits in the In-Band Code Control (IBCC) register. When generating a 1, 2, 4, 8, or 16 bit pattern both the transmit code registers (TCD1 and TCD2) must be filled with the proper code. Generation of a 1, 3, 5, or 7-bit pattern only requires TCD1 to be filled. Once this is accomplished, the pattern will be transmitted as long as the TLCE control bit (CCR3.3) is enabled. As an example, if the user wished to transmit the standard “loop up” code for Channel Service Units which is a repeating pattern of ...10000100001... then 80h would be loaded into TCD1 and the length would set using TC1 and TC0 in the IBCC register to 5 bits.

The DS21348 can detect two separate repeating patterns to allow for both a “loop up” code and a “loop down” code to be detected. The user will program the codes to be detected in the Receive Up Code Definition (RUPCD1 and RUPCD2) registers and the Receive Down Code Definition (RDNCD1 and RDNCD2) registers and the length of each pattern will be selected via the IBCC register. The DS21348 will detect repeating pattern codes with bit error rates as high as 1x10-2. The code detector has a nominal integration period of 48ms, hence, after about 48ms of receiving either code, the proper status bit (LUP at SR.7 and LDN at SR.6) will be set to a one. Normally codes are sent for a period of 5 seconds. It is recommended that the software poll the DS21348 every 100ms to 1000ms until 5 seconds has elapsed to insure that the code is continuously present.

IBCC (0AH): IN-BAND CODE CONTROL REGISTER

(MSB)

TC1 TC0 RUP2 RUP1 RUP0 RDN2 RDN1 RDN0

SYMBOL POSITION DESCRIPTION

TC1 IBCC.7 Transmit Code Length Definition Bit 1. See Table 6-1.

TC0 IBCC.6 Transmit Code Length Definition Bit 0. See Table 6-1

RUP2 IBCC.5 Receive Up Code Length Definition Bit 2. See Table 6-2.

RUP1 IBCC.4 Receive Up Code Length Definition Bit 1. See Table 6-2.

RUP0 IBCC.3 Receive Up Code Length Definition Bit 0. See Table 6-2.

RDN2 IBCC.2 Receive Down Code Length Definition Bit 2. See Table 6-2

RDN1 IBCC.1 Receive Down Code Length Definition Bit 1. See Table 6-2

RDN0 IBCC.0 Receive Down Code Length Definition Bit 0. See Table 6-2.

(LSB)

Table 6-1. Transmit Code Length

41 of 76

TC1 TC0

LENGTH SELECTED

(BITS)

0 0 5 0 1 6/3 1 0 7 1 1 16/8/4/2/1

Table 6-2. Receive Code Length

DS21348/DS21Q348

RUP2/RDN2 RUP1/ RDN1 RUP0/RDN0

LENGTH

SELECTED (BITS)

0 0 0 1 0 0 1 2 0 1 0 3 0 1 1 4 1 0 0 5 1 0 1 6 1 1 0 7 1 1 1 16/8

TCD1 (0BH): TRANSMIT CODE DEFINITION REGISTER 1

(MSB)

C7 C6 C5 C4 C3 C2 C1 C0

SYMBOL POSITION DESCRIPTION

C7 TCD1.7 Transmit Code Definition Bit 7. First bit of the repeating

C6 TCD1.6

C5 TCD1.5

C4 TCD1.4

C3 TCD1.3

C2 TCD1.2 Transmit Code Definition Bit 2. A Don’t Care if a 5-bit

C1 TCD1.1 Transmit Code Definition Bit 1. A Don’t Care if a 5-bit or 6-

C0 TCD1.0 Transmit Code Definition Bit 0. A Don’t Care if a 5-bit, 6-

(LSB)

pattern.

Transmit Code Definition Bit 6.

Transmit Code Definition Bit 5.

Transmit Code Definition Bit 4.

Transmit Code Definition Bit 3.

length is selected.

bit length is selected.

bit, or 7-bit length is selected.

42 of 76

TCD2 (0CH): TRANSMIT CODE DEFINITION REGISTER 2

DS21348/DS21Q348

(MSB)

(LSB)

C15 C14 C13 C12 C11 C10 C9 C8

SYMBOL POSITION DESCRIPTION

C15 TCD2.7

Transmit Code Definition Bit 15

C14 TCD2.6

Transmit Code Definition Bit 14

C13 TCD2.5

Transmit Code Definition Bit 13

C12 TCD2.4

Transmit Code Definition Bit 12

C11 TCD2.3

Transmit Code Definition Bit 11

C10 TCD2.2

Transmit Code Definition Bit 10

C9 TCD2.1

Transmit Code Definition Bit 9

C8 TCD2.0

Transmit Code Definition Bit 8

RUPCD1 (0DH): RECEIVE UP CODE DEFINITION REGISTER 1

(MSB)

(LSB)

C7 C6 C5 C4 C3 C2 C1 C0

SYMBOL POSITION DESCRIPTION

C7 RUPCD1.7 Receive Up Code Definition Bit 7. First bit of the repeating

pattern.

C6 RUPCD1.6 Receive Up Code Definition Bit 6. A Don’t Care if a 1-bit

length is selected.

C5 RUPCD1.5 Receive Up Code Definition Bit 5. A Don’t Care if a 1-bit or

2-bit length is selected.

C4 RUPCD1.4 Receive Up Code Definition Bit 4. A Don’t Care if a 1-bit to

3-bit length is selected.

C3 RUPCD1.3 Receive Up Code Definition Bit 3. A Don’t Care if a 1-bit to

4-bit length is selected.

C2 RUPCD1.2 Receive Up Code Definition Bit 2. A Don’t Care if a 1-bit to

5-bit length is selected.

C1 RUPCD1.1 Receive Up Code Definition Bit 1. A Don’t Care if a 1-bit to

6-bit length is selected.

C0 RUPCD1.0 Receive Up Code Definition Bit 0. A Don’t Care if a 1-bit to

7-bit length is selected.

43 of 76

RUPCD2 (0EH): RECEIVE UP CODE DEFINITION REGISTER 2

DS21348/DS21Q348

(MSB)

(LSB)

C15 C14 C13 C12 C11 C10 C9 C8

SYMBOL POSITION DESCRIPTION

C15 RUPCD2.7

Receive Up Code Definition Bit 15

C14 RUPCD2.6

Receive Up Code Definition Bit 14

C13 RUPCD2.5

Receive Up Code Definition Bit 13

C12 RUPCD2.4

Receive Up Code Definition Bit 12

C11 RUPCD2.3

Receive Up Code Definition Bit 11

C10 RUPCD2.2

Receive Up Code Definition Bit 10

C9 RUPCD2.1

Receive Up Code Definition Bit 9

C8 RUPCD2.0

Receive Up Code Definition Bit 8

RDNCD1 (0FH): RECEIVE DOWN CODE DEFINITION REGISTER 1

(MSB)

(LSB)

C7 C6 C5 C4 C3 C2 C1 C0

SYMBOL POSITION DESCRIPTION

C7 RDNCD1.7 Receive Down Code Definition Bit 7. First bit of the

repeating pattern.

C6 RDNCD1.6 Receive Down Code Definition Bit 6. A Don’t Care if a 1-bit

length is selected.

C5 RDNCD1.5 Receive Down Code Definition Bit 5. A Don’t Care if a 1-bit

or 2-bit length is selected.

C4 RDNCD1.4 Receive Down Code Definition Bit 4. A Don’t Care if a 1-bit

to 3-bit length is selected.

C3 RDNCD1.3 Receive Down Code Definition Bit 3. A Don’t Care if a 1-bit

to 4-bit length is selected.

C2 RDNCD1.2 Receive Down Code Definition Bit 2. A Don’t Care if a 1-bit

to 5-bit length is selected.

C1 RDNCD1.1 Receive Down Code Definition Bit 1. A Don’t Care if a 1-bit

to 6-bit length is selected.

C0 RDNCD1.0 Receive Down Code Definition Bit 0. A Don’t Care if a 1-bit

to 7-bit length is selected.

44 of 76

DS21348/DS21Q348

RDNCD2 (10H): RECEIVE DOWN CODE DEFINITION REGISTER 2

(MSB)

(LSB)

C15 C14 C13 C12 C11 C10 C9 C8

SYMBOL POSITION DESCRIPTION

C15 RDNCD2.7

Receive Down Code Definition Bit 15

C14 RDNCD2.6

Receive Down Code Definition Bit 14

C13 RDNCD2.5

Receive Down Code Definition Bit 13

C12 RDNCD2.4

Receive Down Code Definition Bit 12

C11 RDNCD2.3

Receive Down Code Definition Bit 11

C10 RDNCD2.2

Receive Down Code Definition Bit 10

C9 RDNCD2.1

Receive Down Code Definition Bit 9

C8 RDNCD2.0

Receive Down Code Definition Bit 8

45 of 76

DS21348/DS21Q348

6.2 Loopbacks

6.2.1 Remote Loopback (RLB)

When RLB (CCR6.6) is enabled, the DS21348 is placed into remote loopback. In this loopback, data from the clock/data recovery state machine will be looped back to the transmit path passing through the jitter attenuator if it is enabled. The data at the RPOS and RNEG pins will be valid while data presented at TPOS and TNEG will be ignored. See Figure 1-1 for details.

If the Automatic Remote Loop Back Enable (CCR6.5) is set to a one, the DS21348 will automatically go into remote loop back when it detects the loop-up code programmed in the Receive Up Code Definition Registers (RUPCD1 and RUPCD2) for a minimum of 5 seconds. When the DS21348 detects the loop down code programmed in the Receive Loop-Down Code Definition registers (RDNCD1 and RDNCD2) for a minimum of 5 seconds, the DS21348 will come out of remote loop back. The ARLB can also be disabled by setting ARLBE to a zero.

6.2.2 Local Loopback (LLB)

When LLB (CCR6.7) is set to a one, the DS21348 is placed into Local Loopback. In this loopback, data on the transmit-side will continue to be transmitted as normal. TCLK and TPOS/TNEG will pass through the jitter attenuator (if enabled) and be output at RCLK and RPOS/RNEG. Incoming data from the line at RTIP and RRING will be ignored. If Transmit Unframed All Ones (CCR3.7) is set to a one while in LLB, TTIP and TRING will transmit all ones while TCLK and TPOS/TNEG will be looped back to RCLK and RPOS/RNEG. See Figure 1-1 for more details.

6.2.3 Analog Loopback (ALB)

Setting ALB (CCR6.4) to a one puts the DS21348 in Analog Loopback. Signals at TTIP and TRING will be internally connected to RTIP and RRING. The incoming signals at RTIP and RRING will be ignored. The signals at TTIP and TRING will be transmitted as normal. See Figure 1-1 for more details.

6.2.4 Dual Loopback (DLB)

Setting both CCR6.7 and CCR6.6 to a one, LLB and RLB respectively, puts the DS21348 into Dual Loopback operation. The TCLK and TPOS/TNEG signals will be looped back through the jitter attenuator (if enabled) and output at RCLK and RPOS/RNEG. Clock and data recovered from RTIP and RRING will be looped back to the transmit-side and output at TTIP and TRING. This mode of operation is not available when implementing hardware operation. See Figure 1-1

for more details.

46 of 76

DS21348/DS21Q348

6.3 PRBS Generation and Detection

Setting TPRBSE (CCR3.4) = 1 enables the DS21348 to transmit a 215 - 1 (E1) or a 220 - 1 (T1) PseudoRandom Bit Sequence (PRBS) depending on the ETS bit setting in CCR1.7. The receive-side of the DS21348 will always search for these PRBS patterns independent of CCR3.4. The PRBS Bit Error Output (PBEO) will remain high until the receiver has synchronized to one of the two patterns (64 bits received without an error) at which time PBEO will go low and the PRBSD bit in the Status Register (SR) will be set. Once synchronized, any bit errors received will cause a positive going pulse at PBEO, synchronous with RCLK. This output can be used with external circuitry to keep track of bit error rates during the PRBS testing. Setting CCR6.0 (ECRS) = 1 will allow the PRBS errors to be accumulated in the 16-bit counter in registers ECR1 and ECR2. The PRBS synchronizer will remain in sync until it experiences 6 bit errors or more within a 64-bit span. Both PRBS patterns comply with the ITU-T O.151 specifications.

6.4 Error Counter

Error Count Register 1 (ECR1) is the most significant word and ECR2 is the least significant word of a user selectable 16-bit counter that records incoming errors including BiPolar Violations (BPV), Code Violations (CV), Excessive Zero violations (EXZ) and/or PRBS Errors. See Table 6-3 and Table 6-4 and

Figure 1-2 for details.

Table 6-3. Definition of Received Errors

ERROR E1 OR T1 DEFINITION OF RECEIVED ERRORS

Two consecutive marks with the same polarity. Will ignore BPVs due to

BPV E1/T1

CV E1

EXZ E1 When four or more consecutive zeros are detected.

EXZ T1

PRBS E1/T1

HDB3 and B8ZS zero suppression when CCR2.3 = 0. Typically used with AMI coding (CCR2.3 = 1). ITU-T O.161. When HDB3 is enabled (CCR2.3 = 0) and the receiver detects two consecutive BPVs with the same polarity. ITU-T O.161.

When receiving AMI coded signals (CCR2.3 = 1), detection of 16 or more zeros or a BPV. ANSI T1.403 1999. When receiving B8ZS coded signals (CCR2.3 = 0), detection of 8 or more zeros or a BPV. ANSI T1.403 1999. A bit error in a received PRBS pattern. See Section 6.3 for details. ITU-T O.151.

47 of 76

Table 6-4. Function of ECRS Bits and RNEG Pin

DS21348/DS21Q348

E1 or T1

(CCR1.7)

ECRS2

(CCR6.2)

ECRS1

(CCR6.1)

ECRS0

(CCR6.0)

RHBE

(CCR2.3)

FUNCTION OF ECR

COUNTERS/RNEG1

0 0 0 0 X CVs 0 0 0 1 X BPVs (HDB3 code words not counted) 0 0 1 0 X CVs + EXZs 0 0 1 1 X BPVs + EXZs 1 0 X 0 0 BPVs (B8ZS code words not counted) 1 0 X 1 0 BPVs + 8 EXZs 1 0 X 0 1 BPVs 1 0 X 1 1 BPVs + 16 EXZs

X 1 X X X PRBS Errors

Note 1:

Note 2:

RNEG outputs error data only when in NRZ mode (CCR1.6 = 1)

PRBS errors will always be output at PBEO independent of ECR control bits and NRZ mode and will not be present at RNEG.

6.4.1 Error Counter Update

A transition of the ECUE (CCR1.4) control bit from 0 to 1 will update the ECR registers with the current values and reset the counters. ECUE must be set back to zero and another 0 to 1 transition must occur for subsequent reads/resets of the ECR registers. Note that the DS21348 can report errors at RNEG when in NRZ mode (CCR1.6 = 1) by outputting a pulse for each error occurrence. The counter saturates at 65,535 and will not rollover.

ECR1 (11H): UPPER ERROR COUNT REGISTER 1; ECR2 (12H): LOWER ERROR COUNT REGISTER 2

(MSB)

(LSB)

E15 E14 E13 E12 E11 E10 E9 E8 ECR1

E7 E6 E5 E4 E3 E2 E1 E0 ECR2

SYMBOL POSITION DESCRIPTION

E15 ECR1.7

MSB of the 16-bit error count

E0 ECR2.0

LSB of the 16-bit error count

6.5 Error Insertion

When IBPV (CCR3.1) is transitioned from a zero to a one, the device waits for the next occurrence of three consecutive ones to insert a BPV. IBPV must be cleared and set again for another BPV error insertion. See Figure 1-3

When IBE (CCR3.0) is transitioned from a zero to a one, the device will insert a logic error. IBE must be cleared and set again for another logic error insertion. See Figure 1-3 logic error into the datasteam.

for details on the insertion of the BPV into the datastream.

for details on the insertion of the

48 of 76

DS21348/DS21Q348

7. ANALOG INTERFACE

7.1 Receiver

The DS21348 contains a digital clock recovery system. The DS21348 couples to the receive E1 or T1 twisted pair (or coaxial cable in 75Ω E1 applications) via a 1:1 transformer. See Table 7-3 for transformer details. Figure 7-1 termination requirements. The DS21348 has the option of using internal termination resistors.

The DS21348 is designed to be fully software-selectable for E1 and T1 without the need to change any external resistors for the receive-side. The receive-side will allow the user to configure the DS21348 for 75Ω, 100Ω, or 120Ω receive termination by setting the RT1 (CCR5.1) and RT0 (CCR5.0) bits. When using the internal termination feature, the Rr resistors should be 60Ω each. See Figure 7-1 external termination is required, RT1 and RT0 should be set to 0 and both Rr resistors in Figure 7-1 will need to be 37.5Ω, 50Ω, or 60Ω each depending on the line impedance.

The resultant E1 or T1 clock derived from the 2.048/1.544 PLL (JACLK in Figure 1-1) is internally multiplied by 16 via another internal PLL and fed to the clock recovery system. The clock recovery system uses the clock from the PLL circuit to form a 16 times oversampler which is used to recover the clock and data. This oversampling technique offers outstanding performance to meet jitter tolerance specifications shown in Figure 7-6.

, Figure 7-2, and Figure 7-3 along with Table 7-1 and Table 7-2 show the receive

for details. If

Normally, the clock that is output at the RCLK pin is the recovered clock from the E1 AMI/HDB3 or T1 AMI/B8ZS waveform presented at the RTIP and RRING inputs. When no signal is present at RTIP and RRING, a Receive Carrier Loss (RCL) condition will occur and the RCLK will be derived from the JACLK source. See Figure 1-1. If the jitter attenuator is placed in the receive path (as is the case in most applications), the jitter attenuator restores the RCLK to an approximate 50% duty cycle. If the jitter attenuator is either placed in the transmit path or is disabled, the RCLK output can exhibit slightly shorter high cycles of the clock. This is due to the highly oversampled digital clock recovery circuitry. See the Receive AC Timing Characteristics in Section 11 for more details.

The receive-side circuitry also contains a clock synthesizer which outputs a user configurable clock (up to

16.384MHz) synthesized to RCLK at BPCLK (pin 31). See Table 4-3 for details on output clock frequencies at BPCLK. In hardware mode, BPCLK defaults to a 16.384MHz output.

The DS21348 has a bypass mode for the receive side clock and data. This allows the BPCLK to be derived from RCLK after the jitter attenuator while the clock and data presented at RCLK, RPOS, and RNEG go unaltered. This is intended for applications where the receive side jitter attenuation will be done after the LIU. Setting RJAB (CCR6.3) to a logic 1 will enable the bypass. Be sure that the jitter attenuator is in the receive path (CCR4.3 = 0). See Figure 1-1

for details.

The DS21348 will report the signal strength at RTIP and RRING in 2.5dB increments via RL3-RL0 located in the Receive Information Register 2. This feature is helpful when trouble shooting line performance problems. See Table 5-2 for details.

Monitor applications in both E1 and T1 require various flat gain settings for the receive-side circuitry. The DS21348 can be programmed to support these applications via the Monitor Mode control bits MM1 and MM0. When the monitor modes are enabled, the receiver will tolerate normal line loss up to -6dB. See Table 4-4

for details.

49 of 76

DS21348/DS21Q348

7.2 Transmitter

The DS21348 uses a set of laser-trimmed delay lines along with a precision Digital-to-Analog Converter (DAC) to create the waveforms that are transmitted onto the E1 or T1 line. The waveforms created by the DS21348 meet the latest ETSI, ITU, ANSI, and AT&T specifications. The user will select which waveform is to be generated by setting the ETS bit (CCR1.7) for E1 or T1 operation, then programming the L2/L1/L0 bits in Common Control Register 4 for the appropriate application. See Table 7-1 and

Table 7-2 for the proper L2/L1/L0 settings.

A 2.048MHz or 1.544MHz TTL clock is required at TCLK for transmitting data at TPOS and TNEG. ITU specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces. The clock can be sourced internally by RCLK or JACLK. See CCR1.2, CCR1.1, CCR1.0, and Figure 1-3 transmitter in the DS21348, very little jitter (less than 0.005UI added to the jitter present on TCLK. Also, the waveforms created are independent of the duty cycle of TCLK. The transmitter in the DS21348 couples to the E1 or T1 transmit twisted pair (or coaxial cable in some E1 applications) via a 1:2 step-up transformer. In order for the device to create the proper waveforms, the transformer used must meet the specifications listed in Table 7-3.

The DS21348 has automatic short-circuit limiter which limits the source current to 50mA (RMS) into a 1Ω load. This feature can be disabled by setting the SCLD bit (CCR2.5) = 1. When the current limiter is activated, TCLE (SR.2) will be set even if short circuit limiter is disabled. The TPD bit (CCR4.0) will power-down the transmit line driver and tri-state the TTIP and TRING pins. The DS21348 can also detect when the TTIP or TRING outputs are open circuited. When an open circuit is detected, TOCD (SR.1) will be set.

for details. Due to the nature of the design of the

broadband from 10Hz to 100kHz) is

P-P

7.3 Jitter Attenuator

The DS21348 contains an on-board jitter attenuator that can be set to a depth of either 32 or 128 bits via the JABDS bit (CCR4.2). In hardware mode the depth is 128 bits and cannot be changed. The 128-bit mode is used in applications where large excursions of wander are expected. The 32-bit mode is used in delay sensitive applications. The characteristics of the attenuation are shown in Figure 7-7Figure 7-7. The jitter attenuator can be placed in either the receive path or the transmit path by appropriately setting or clearing the JAS bit (CCR4.3). Also, the jitter attenuator can be disabled (in effect, removed) by setting the DJA bit (CCR4.1). For the jitter attenuator to operate properly, a 2.048MHz or 1.544MHz clock must be applied at MCLK. ITU specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces. There is an on-board PLL for the jitter attenuator, which will convert the 2.048MHz clock to a 1.544 MHz rate for T1 applications. Setting JAMUX (CCR1.3) to a logic 0 bypasses this PLL. On-board circuitry adjusts either the recovered clock from the clock/data recovery block or the clock applied at the TCLK pin to create a smooth jitterfree clock, which is used to clock data out of the jitter attenuator FIFO. It is acceptable to provide a gapped/bursty clock at the TCLK pin if the jitter attenuator is placed on the transmit side. If the incoming jitter exceeds either 120UI

(buffer depth is 128 bits) or 28UI

P-P

DS21348 will divide the internal nominal 32.768MHz (E1) or 24.704MHz (T1) clock by either 15 or 17 instead of the normal 16 to keep the buffer from overflowing. When the device divides by either 15 or 17, it also sets the Jitter Attenuator Limit Trip (JALT) bit in the Receive Information Register 1 (RIR1).

(buffer depth is 32 bits), then the

P-P

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DS21348/DS21Q348

7.4 G.703 Synchronization Signal

The DS21348 can receive a 2.048MHz square-wave synchronization clock as specified in Section 13 of ITU G.703(10/98). To use the DS21348 in this mode, set the Receive Synchronization Clock Enable (CCR5.3) = 1. The DS21348 can also transmit the 2.048MHz square-wave synchronization clock as specified in Section 10 of G.703. To transmit the 2.048MHz clock, set the Transmit Synchronization Clock Enable (CCR5.2) = 1.

Table 7-1. Line Build-Out Select for E1 in Register CCR4 (ETS = 0)

L2 L1 L0

VDD

(V)

0 0 0 3.3 0 0 1 3.3 1 0 0 3.3 1 0 1 3.3

APPLICATION N

75Ω normal 120Ω normal 75Ω with high return loss 120Ω with high return loss

1:2 N.M. 0 1:2 N.M. 0 1:2 21 6.2 1:2 21 11.6

RETURN LOSS

(dB)

Rt (Ω)

Note: See Figure 7-1, Figure 7-2, and Figure 7-3. N.M. = Not meaningful.

Table 7-2. Line Build-Out Select for T1 in Register CCR4 (ETS = 1)

L2 L1 L0

0 0 0 3.3

VDD

(V)

APPLICATION N

DSX-1 (0 to 133 feet)/ 0dB CSU

1:2 N.M. 0

0 0 1 3.3 DSX-1 (133 to 266 feet) 1:2 N.M. 0 0 1 0 3.3 DSX-1 (266 to 399 feet) 1:2 N.M. 0 0 1 1 3.3 DSX-1 (399 to 533 feet) 1:2 N.M. 0 1 0 0 3.3 DSX-1 (533 to 655 feet) 1:2 N.M. 0 1 0 1 3.3 -7.5dB CSU 1:2 N.M. 0 1 1 0 3.3 -15dB CSU 1:2 N.M. 0 1 1 1 3.3 -22.5dB CSU 1:2 N.M. 0

Note: See Figure 7-1, Figure 7-2, and Figure 7-3. N.M. = Not meaningful.

RETURN LOSS

(dB)

Rt (Ω)

Table 7-3. Transformer Specifications for 3.3V Operation

SPECIFICATION RECOMMENDED VALUE

Turns Ratio 3.3V Applications 1:1 (receive) and 1:2 (transmit) ±2% Primary Inductance Leakage Inductance Intertwining Capacitance 40pF maximum Transmit Transformer DC Resistance

Primary (Device Side) Secondary

Receive Transformer DC Resistance

Primary (Device Side) Secondary

600µH minimum

1.0µH maximum

1.0Ω maximum

2.0Ω maximum

1.2Ω maximum

51 of 76

DS21348/DS21Q348

rRr

Figure 7-1. Basic Interface

Transmit

Line

N:1

(larger winding

toward the network)

1.0µF (non-

polarized)

DS21348

TTIP

TRING

VDD (21) VSS (22)

VDD (36)

VSS (35)

0.1µF

0.01µF

0.1µF

Receive

Line

1:1

RTIP

RRING

MCLK

2.048MHz (this clock can also be 1.544MHz for T1 only applications)

0.1µF

NOTES:

1) All resistor values are ±1%.

2) In E1 applications, the Rt resistors are used to increase the transmitter return loss (Table 7-1). No return loss is required for T1 applications.

3) The Rr resistors should be set to 60Ω each if the internal receive-side termination feature is enabled. When this feature is disabled, Rr = 37.5Ω for 75Ω or 60Ω for 120Ω E1 systems, or 50Ω for 100Ω T1 lines.

4) See Table 7-1

and Table 7-2 for the appropriate transmit transformer turns ratio (N).

+VDD

10µF

52 of 76

DS21348/DS21Q348

Figure 7-2. Protected Interface Using Internal Receive Termination

Transmit

Line

(optional)

Fuse

N:1

(larger winding

toward the network)

1.0µF (non-

polarized)

D3 D4

Receive

Line

Fuse

(optional)

1:1

60 60

0.1µF

NOTES:

1. All resistor values are ±1%.

2. C1 = C2 = 0.1µF.

3. S is a 6V transient suppresser.

4. D1 to D8 are Schottky diodes.

5. The fuses are optional to prevent AC power line crosses from compromising the transformers.

6. Rp resistors exist to keep the Fuses from opening during a surge. If they are used, then the 60Ω receive termination resistance must be adjusted to match the line impedance.

7. The Rt resistors are used to increase the transmitter return loss (Table 7-1 for T1 applications.

8. The transmit transformer turns ratio (N) would be 1:2 for 3.3V operation.

9. The 68µF is used to keep the local power plane potential within tolerance during a surge.

+VDD

TTIP

TRING

RTIP

RRING

DS21348

VDD (21)

VSS (22)

VDD (36)

VSS (35)

MCLK

+VDD

0.1µF

0.01µF

10µF

0.1µF

10µF

2.048MHz (this clock can also be 1.544MHz for T1 only applications)

68µF

). No return loss is required

53 of 76

DS21348/DS21Q348

rRr

Figure 7-3. Protected Interface Using External Receive Termination

Transmit

Line

(optional)

Fuse

N:1

(larger winding

toward the network)

1.0µF (non-

polarized)

D3 D4

(optional)

1:1

470

Receive

Line

Fuse

0.1µF

NOTES:

1. All resistor values are ±1%.

2. C1 = 0.1µF.

3. S is a 6V transient suppresser.

4. D1 to D4 are Schottky diodes.

5. The fuses are optional to prevent AC power line crosses from compromising the transformers.

6. Rp resistors exist to keep the Fuses from opening during a surge. If they are used, then Rr must be adjusted to match the line impedance.

7. Rr = 37.5Ω for 75Ω or 60Ω for 120Ω E1 systems, or 50Ω for 100Ω T1 lines.

8. The Rt resistors are used to increase the transmitter return loss (Table 7-1). No return loss is required for T1 applications.

9. The transmit transformer turns ratio (N) would be 1:2 for 3.3V operation.

10. The 68µF is used to keep the local power plane potential within tolerance during a surge.

+VDD

TTIP

TRING

RTIP

RRING

DS21348

VDD (21)

VSS (22)

VDD (36)

VSS (35)

MCLK

0.1µF

0.01µF

10µF

0.1µF

10µF

2.048MHz (this clock can also be 1.544MHz for T1 only applications)

+VDD

68µF

54 of 76

Figure 7-4. E1 Transmit Pulse Template

1.2

DS21348/DS21Q348

SCALED AMPLITUDE

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

(in 75 ohm systems, 1.0 on the scale = 2.37Vpeak

in 120 ohm systems, 1.0 on the scale = 3.00Vpeak)

-0.1

-0.2

194ns

219ns

TIME (ns)

50 100 150 200 250-50-100-150-200-250

269ns

G.703

Template

55 of 76

Figure 7-5. T1 Transmit Pulse Template

1.2

1.1

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

NORMALIZED AMPLITUDE

-0.1

-0.2

-0.3

T1.102/87, T1.403, CB 119 (Oct. 79), & I.431 Template

MAXIMUM CURVE

UI Time Amp.

-0.77

-500

-255

-175

-75 0 175 225 600 750

0.05

0.80

1.15

1.05

-0.07

0.05

-0.39

-0.27

-0.12

0.00

0.27

0.35

0.93

1.16

MINIMUM CURVE

UI Time Amp.

-0.77

-500

-150

-100 0 100 150 150 300 430 600 750

-0.05

0.50

0.95

0.90

0.50

-0.45

-0.20

-0.05

-0.23

-0.15

0.00

0.15

0.23

0.46

0.66

0.93

1.16

DS21348/DS21Q348

-0.4

-0.5

-500 -300 -100 0 300 500 700

-400 -200 200 400 600100

TIME (ns)

56 of 76

Figure 7-6. Jitter Tolerance

100

)

P-P

UNIT INTERVALS (UI

0.1 1

TR 62411 (Dec. 90)

10 100 1k 10k 100k

DS21348/DS21Q348

DS21348

Tolerance

ITU-T G.823

FREQUENCY (Hz)

Figure 7-7. Jitter Attenuation

0dB

-20dB

-40dB

JITTER ATTENUATION (dB)

-60dB

1 10 100 1K 10K

Prohibited

TBR12

Area

ve A

T1E1

FREQUENCY (Hz)

ITU G.7XX

Prohibited Area

TR 62411 (Dec. 90)

Prohibited Area

100K

57 of 76

DS21348/DS21Q348

8. DS21Q348 QUAD LIU

The DS21Q348 is a quad version of the DS21348G utilizing CSBGA on carrier packaging technology. The four LIUs are controlled via the parallel port mode. Serial and hardware modes are unavailable in this package.

Table 8-1. DS21Q348 Pin Assignment

PIN I/O

PARALLEL

PORT MODE

J1 I Connect to VSS

K3 I Connect to VSS

J2 I

H1 I

RD (DS)

WR (R/W)

K2 I ALE (AS) K1 I/O A4

L1 I A3 H11 I A2 H12 I A1 G12 I A0

J10 I/O D7/AD7 H10 I/O D6/AD6 G11 I/O D5/AD5

J9 I/O D4/AD4

E3 I/O D3/AD3

D4 I/O D2/AD2

F3 I/O D1/AD1 D5 I/O D0/AD0 G4 I VSM K9 I/O

INT

K7 I TEST

L9 I

HRST

J6 I MCLK

L7 I BIS0

M8 I BIS1

M12 I PBTS

J3 I

D3 I

D10 I K10 I

CS1 CS2 CS3 CS4

K5 O PBEO1 G3 O PBEO2

E10 O PBEO3

K8 O PBEO4

L6 O RCL/LOTC1 D7 O RCL/LOTC2

58 of 76

PIN I/O

PARALLEL

PORT MODE

F9 O RCL/LOTC3

J7 O RCL/LOTC4 A1 I RTIP1 A4 I RTIP2 A7 I RTIP3

A10 I RTIP4

B2 I RRING1 B5 I RRING2 B8 I RRING3

B11 I RRING4

H4 O BPCLK1 D6 O BPCLK2

F10 O BPCLK3

L8 O BPCLK4 A2 O TTIP1 A5 O TTIP2 A8 O TTIP3

A11 O TTIP4

B3 O TRING1

B6 O TRING2

B9 O TRING3

B12 O TRING4

K4 O RPOS1

E1 O RPOS2

D11 O RPOS3 K11 O RPOS4

G2 O RNEG1

E2 O RNEG2

F11 O RNEG3

M10 O RNEG4

H3 O RCLK1

F1 O RCLK2

E11 O RCLK3 L11 O RCLK4

G1 I TPOS1

F2 I TPOS2

E12 I TPOS3

M11 I TPOS4

H2 I TNEG1

M1 I TNEG2 D12 I TNEG3 K12 I TNEG4

M2 I TCLK1

L2 I TCLK2

59 of 76

DS21348/DS21Q348

PIN I/O

PARALLEL

PORT MODE

F12 I TCLK3 L12 I TCLK4

J5 — VDD1 D2 — VDD2 G9 — VDD3

M9 — VDD4

L5 — VDD1 E4 — VDD2

D8 — VDD3

J8 — VDD4

J4 — VSS1 D1 — VSS2

E9 — VSS3

L10 — VSS4

M4 — VSS1

F4 — VSS2 D9 — VSS3 H9 — VSS4

DS21348/DS21Q348

60 of 76

Figure 8-1. 144-CSBGA (17mm x 17mm) Pinout

1 2 3 4 5 6 7 8 9 10 11 12

RTIP1 TTIP1 NC RTIP2 TTIP2 NC RTIP3 TTIP3 NC RTIP4 TTIP4 NC

DS21348/DS21Q348

J (Note 2)

NC RRING1 TRING1 NC RRING2 TRING2 NC RRING3 TRING3 NC RRING4 TRING4

NC NC NC NC NC NC NC NC NC NC NC NC

VSS2 VDD2

RPOS2 RNEG2 D3/AD3 VDD2 NC NC NC NC VSS3 PEBO3 RCLK3 TPOS3

RCLK2 TPOS2 D1/AD1 VSS2 NC NC NC NC

TPOS1 RNEG1 PEBO2 VSM NC NC NC NC

(R/W)

A4 ALE (AS)

A3 TCLK2 NC NC VDD1

TNEG2 TCLK1 NC VSS1 NC NC NC BIS1 VDD4 RNEG4 TPOS4 PBTS

TNEG1 RCLK1 BPCLK1 NC NC NC NC VSS4 D6/AD6 A2 A1

(DS)

CS2

CS1

(Note 2)

D2/AD2 D0/AD0 BPCLK2

VSS1 VDD1 MCLK

RPOS1 PEBO1 NC TEST PEBO4

RCL/

LOTC1

Note 1: Shaded areas are signals common to all four devices. Note 2: Connect to V

RCL/

LOTC2

RCL/

LOTC4

BIS0 BPCLK4

VDD3 VSS3

VDD4 D4/AD4 D7/AD7 NC NC

RCL/

LOTC3

VDD

HRST

BPCLK3 RNEG3 TCLK3

INT CS4

CS3

NC D5/AD5 A0

VSS4 RCLK4 TCLK4

RPOS3 TNEG3

RPOS4 TNEG4

61 of 76

DS21348/DS21Q348

9. DC CHARACTERISTICS

ABSOLUTE MAXIMUM RATINGS

Voltage Range on Any Pin Relative to Ground……………………………………………..-1.0V to +6.0V Operating Temperature Range for DS21348TN……………………………………………-40°C to +85°C

Storage Temperature Range……………………………………………………………….-55°C to +125°C Soldering Temperature………………………………………….See IPC/JEDEC J-STD-020 Specification

This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time can affect device reliability.

Table 9-1. Recommended DC Operating Conditions

(TA = -40°C to +85°C)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Logic 1 VIH 2.0 5.5 V Logic 0 VIL –0.3 +0.8 V Supply for 3.3V Operation VDD 3.135 3.3 3.465 V 1

Table 9-2. Capacitance

(TA = +25°C)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Input Capacitance CIN 5 pF Output Capacitance C

7 pF

OUT

Table 9-3. DC Characteristics

(VDD = 3.3V ± 5%, TA = -40°C to +85°C.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Input Leakage IIL -1.0 +1.0 Output Leakage ILO 1.0

µA µA

Output Current (2.4V) IOH –1.0 mA Output Current (0.4V) IOL +4.0 mA Supply Current IDD 66 100 mA 2, 5

NOTES:

1) Applies to VDD.

2) TCLK = MCLK = 2.048MHz.

3) 0.0V < V

< VDD.

4) Applied to INT when tri-stated.

5) Power dissipation with TTIP and TRING driving a 30Ω load, for an all-ones data density.

3 4

62 of 76

DS21348/DS21Q348

10. THERMAL CHARACTERISTICS

Table 10-1. Thermal Characteristics—DS21Q348 CSBGA Package

PARAMETER MIN TYP MAX NOTES

Ambient Temperature -40ºC +85ºC 1 Junction Temperature +125ºC Theta-JA (θJA) in Still Air +24ºC/W 2 Theta-JC (θJC) in Still Air +4.1ºC/W 3

NOTES:

1) The package is mounted on a four-layer JEDEC-standard test board.

2) Theta-JA (θ layer JEDEC-standard test board.

3) While Theta-JC (θ junction temperature (Tj) and the average temperature on top center of four of the chip-scale BGA packages (TC), the proper term is Psi-JT. It is defined by:

The method of measurement of the thermal parameters is defined in EIA/JEDEC-standard document EIA-JESD51-2.

) is the junction to ambient thermal resistance, when the package is mounted on a four-

) is commonly used as the thermal parameter that provides a correlation between the

(TJ - TC) / overall package power

Table 10-2. Theta-JA (θJA) vs. Airflow

FORCED AIR (m/s) THETA-JA (θJA)

0 24ºC/W 1 21ºC/W

2.5 19ºC/W

63 of 76

DS21348/DS21Q348

11. AC CHARACTERISTICS

Table 11-1. AC Characteristics—Multiplexed Parallel Port (BIS1 = 0, BIS0 = 0)

(VDD = 3.3V ± 5%, TA = -40°C to +85°C.) (See Figure 11-1, Figure 11-2, and Figure 11-3.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Cycle Time t

Pulse Width, DS Low or RD High

Pulse Width, DS High or RD Low

200 ns

CYC

100 ns

PWEH 100 ns

Input Rise/Fall Times tR, tF 20 ns

R/W Hold Time

R/W Setup Time Before DS High

CS Setup Time Before DS, WR, or RD Active

CS Hold Time

Read Data Hold Time t

Write Data Hold Time t

10 ns

RWH

50 ns

RWS

tCS 20 ns

tCH 0 ns

10 50 ns

DHR

0 ns

DHW

Muxed Address Valid to AS or ALE Fall

Muxed Address Hold Time t

Delay Time DS, WR, or RD to AS or ALE Rise

Pulse Width AS or ALE High

Delay Time, AS or ALE to DS, WR, or RD Output Data Delay Time from DS or RD

Data Setup Time t

15 ns

ASL

10 ns

AHL

20 ns

ASD

30 ns

ASH

10 ns

ASED

20 80 ns

DDR

50 ns

DSW

64 of 76

DS21348/DS21Q348

RD W

Figure 11-1. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 0)

ALE

ASD

ASH

AD0-AD7

ASL

AHL

ASED

CYC

DDR

DHR

Figure 11-2. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 0)

CYC

ALE

ASL

ASH

ASED

AHL

DSW

DHW

AD0-AD7

ASD

65 of 76

DS21348/DS21Q348

W C

Figure 11-3. Motorola Bus Timing (PBTS = 1, BIS1 = 0, BIS0 = 0)

DHR

DHW

D0-AD7

(read)

D0-AD7 (write)

RWS

SED

CYC

DDR

DSW

RWH

66 of 76

DS21348/DS21Q348

Table 11-2. AC Characteristics—Nonmultiplexed Parallel Port (BIS1 = 0, BIS0 = 1)

(VDD = 3.3V ± 5%, TA = -40°C to +85°C.) (See Figure 11-4, Figure 11-5, Figure 11-6, and

Figure 11-7.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Setup Time for A0 to A4, Valid to CS Active

Setup Time for CS Active to Either RD, WR, or DS Active

Delay Time from Either RD or DS Active to Data Valid

Hold Time from Either RD, WR, or DS, Inactive to CS Inactive

Hold Time from CS Inactive to Data Bus Tri-State

Wait Time from Either WR or DS Active to Latch Data

Data Setup Time to Either WR or DS Inactive

Data Hold Time from Either WR or DS Inactive

Address Hold from Either WR or DS Inactive

t1 0 ns

t2 0 ns

t3 75 ns

t4 0 ns

t5 5 20 ns

t6 75 ns

t7 10 ns

t8 10 ns

t9 10 ns

67 of 76

DS21348/DS21Q348

WR CS R

RD CS W

Figure 11-4. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 1)

A0 to A4

Address Valid

D0 to D7

Data Valid

5ns min/20ns max

0ns min.

t2 t3 t4

75ns max.

0ns min.

Figure 11-5. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 1)

A0 to A4

Address Valid

D0 to D7

t7 t8

0ns min.

10ns min.

0ns min.

t2 t6 t4

75ns min.

10ns min.

0ns min.

68 of 76

DS21348/DS21Q348

CS D

Figure 11-6. Motorola Bus Read Timing (PBTS = 1, BIS1 = 0, BIS0 = 1)

A0 to A4

Address Valid

D0 to D7

R/W

0ns min.

t2 t3 t4

75ns max.

Data Valid

5ns min. / 20ns max.

0ns min.

Figure 11-7. Motorola Bus Write Timing (PBTS = 1, BIS1 = 0, BIS0 = 1)

A0 to A4

D0 to D7

R/W

0ns min.

Address Valid

10ns min.

0ns min.

t2 t6 t4

75ns min.

10ns min.

0ns min.

69 of 76

Table 11-3. AC Characteristics—Serial Port (BIS1 = 1, BIS0 = 0)

(VDD = 3.3V ± 5%, TA = -40°C to +85°C.) (See Figure 11-8.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

DS21348/DS21Q348

Setup Time CS to SCLK t Setup Time SDI to SCLK t Hold Timfe SCLK to SDI t SCLK High/Low Time t SCLK Rise/Fall Time t SCLK to CS Inactive t

50 ns

CSS

50 ns

SSS

50 ns

SSH

200 ns

SLH

50 ns

SRF

50 ns

LSC

CS Inactive Time tCM 250 ns SCLK to SDO Valid t SCLK to SDO Tri-State t CS Inactive to SDO Tri-State t

50 ns

SSV

100 ns

SSH

100 ns

CSH

Figure 11-8. Serial Bus Timing (BIS1 = 1, BIS0 = 0)

SCLK

SDI

SDO

SRF

MSB

SLH

LSB

SSV

LSB

CSS

SSS

LSB MSB

SSH

HIGH Z

NOTE 1: OCES =1 AND ICES = 0. NOTE 2: OCES = 0 AND ICES = 1.

LSC

MSB

SSH

HIGH Z

CSH

70 of 76

Table 11-4. AC Characteristics—Receive Side

(VDD = 3.3V ± 5%, TA = -40°C to +85°C.) (See Figure 11-9.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

DS21348/DS21Q348

RCLK Period tCP

488 ns 1

648 ns 2

tCH

200 ns 3

RCLK Pulse Width

tCL

tCH

200 ns 3

150 ns 4

RCLK Pulse Width

Delay RCLK to RPOS, RNEG, PBEO, RBPV Valid

tDD 50 ns

150 ns 4

NOTES:

1) E1 mode.

2) T1 or J1 mode.

3) Jitter attenuator enabled in the receive path.

4) Jitter attenuator disabled or enabled in the transmit path.

Figure 11-9. Receive Side Timing

RCLK

RPOS, RNEG

PBEO

RNEG

bit error

NOTE 1: RCES = 1 (CCR2.0) OR CES = 1. NOTE 2: RCES = 0 (CCR2.0) OR CES = 0. NOTE 3: RNEG IS IN NRZ MODE (CCR1.6 = 1).

BPV/ EXZ/ CV

PRBS Detector Out of Sync

BPV/ EXZ/ CV

71 of 76

Table 11-5. AC Characteristics—Transmit Side

(VDD = 3.3V ± 5%, TA = -40°C to +85°C.) (Figure 11-10)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

TCLK Period tCP

TCLK Pulse Width

tCH 75 ns

tCL 75 ns

488 ns 1 648 ns 2

DS21348/DS21Q348

TPOS/TNEG Setup to TCLK Falling or Rising

TPOS/TNEG Hold from TCLK Falling or Rising

tSU 20 ns

tHD 20 ns

TCLK Rise and Fall Times tR, tF 25 ns

NOTES:

1) E1 mode.

2) T1 or J1 mode.

Figure 11-10. Transmit Side Timing

TCLK

TPOS, TNEG

NOTE 1: TCES = 0 (CCR2.1) or CES = 0. NOTE 2: TCES = 1 (CCR2.1) or CES = 1.

72 of 76

DS21348/DS21Q348

12. PACKAGE INFORMATION

(The package drawing(s) in this data sheet may not reflect the most current specifications. The package number provided for each package is a link to the latest package outline information.)

12.1 44-Pin TQFP (56-G4012-001)

SUGGESTED PAD LAYOUT

44 PIN TQFP, 10*10*1.0

SEE DETAIL "A"

DIMENSIONS ARE IN MILLIMETERS

73 of 76

12.2 49-Ball CSGBA (7mm x 7mm) (56-G6006-001)

DS21348/DS21Q348

74 of 76

12.3 144-Ball CSBGA (17mm x 17mm) (56-G6011-001)

1 CORNER

12 11 10 9 8 7 6 5 4 3 2 1

DS21348/DS21Q348

A1 CORNER

A B C D E F G H I J K L

17.00

0.20

1.52

1.27

13.97

1.52

DETAIL A

0.05

1.27

13.97

2.6 0

0.76

0.6

0.5

1.99

DETAIL B

75 of 76

DS21348/DS21Q348

SOLDER BALL

2.60 REF

0.76 REF

φ 0.76 REF

0.05 LABEL THICKNESS

SEATING PLANE

0.76

X Z Y Z

0.24

/ /

0.17

0.10

76 of 76

Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor product. No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

are registered trademarks of Maxim Integrated Products, Inc., and Dallas Semiconductor Corporation.

MAXIM DS21348, DS21Q348 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

TABLE OF CONTENTS

LIST OF FIGURES