Datasheet CAM35C44 Datasheet (Standard Microsystems Corporation)

CAM35C44

ADVANCE INFORMATION

Infrared Communications Controller Chip

CameraFR

FEATURES

!"

Mixed Voltage Support

- Supports 3.3V Operation

- Supports Mixed Internal 3.3V
Operation with 3.3V/5V External
Configuration

!"

Intelligent Auto Power Management

- Supports Multiple Power Down
Modes

!"

Serial Port

- High Speed NS16C550A Compatible
UART with 16-Byte Send/Receive
FIFOs

- Programmable Baud Rate Generator

!"

Infrared Port

- Multi-Protocol Infrared Interface

- 128-Byte Data FIFO

- IrDA 1.1 Compliant (up to 4Mbps)

- Consumer IR

- SHARP ASK IR

- Programmed I/O and DMA Options

GENERAL DESCRIPTION

The CAM35C44 with IrDA v1.1 (4Mbps) and
Consumer IR support incorporates SMSC’s
advanced Infrared Communications Controller
(IrCC 2.0), a 16C550A-compatible UART,
Multiple Host Interface options, flexible Address
Decoding and up to five General Purpose I/Os.

!"
!"

- ISA-Style 5 Bit Address and 8 Bit
Data Bus

- IOCHRDY and No Wait State Support
for Fast IR

- Non-ISA 8 Bit Multiplexed
Address/Data Bus

- Programmable Read/Write Interface

- One 8 Bit DMA Channel

- One Programmable IRQ

- Chip Select

- Multihost Interface Support Includes
Hitachi and Mitsubishi
Microcontrollers

!"

- Supports Internal or External Clock
Source

!"

The CAM35C44 also features sophisticated
power control circuitry to support multiple power
down modes, an on-chip 24MHz crystal
oscillator, and

The CAM35C44 is particularly suited for 3.3v
battery-powered systems.

Up to 5 General Purpose I/O Pins
Programmable Multi-Protocol Host Interface

24MHz Crystal Oscillator

48 Pin TQFP Package

12mA

host bus drivers.

TABLE OF CONTENTS

FEATURES.............................................................................................................................................. 1

GENERAL DESCRIPTION......................................................................................................................1

ARCHITECTURE.....................................................................................................................................4

PIN CONFIGURATION............................................................................................................................5

DESCRIPTION OF PIN FUNCTIONS......................................................................................................6

UFFER-TYPE SUMMARY

B

........................................................................................................................... 11

CLOCK GENERATOR........................................................................................................................... 12

MULTIHOST CPU INTERFACE............................................................................................................ 13

OST INTERFACE SELECT

H

OST INTERFACE PIN MULTIPLEXING

H

.......................................................................................................................... 14

........................................................................................................... 14

System Data Bus ................................................................................................................................... 14

ISA Address Bus SA0 - SA1..................................................................................................................15

ISA Address Bus SA2 - SA4..................................................................................................................15

ISA nIOR................................................................................................................................................15

ISA nIOW...............................................................................................................................................15

REGISTER ADDRESS MAP..................................................................................................................16

ULTIPLEXED

NON-M

ULTIPLEXED ADDRESSING

M

DDRESSING

(ISA) A

....................................................................................................... 16

........................................................................................................................ 17

CONFIGURATION.................................................................................................................................18

ONFIGURATION ACCESS PORTS

C

ONFIGURATION STATE

C

ONFIGURATION REGISTERS

C

............................................................................................................................. 19

................................................................................................................ 18

...................................................................................................................... 21

INFRARED INTERFACE.......................................................................................................................30

IRDA SIR/FIR ......................................................................................................................................... 30

ASKIR .................................................................................................................................................... 30

ONSUMER

C

ARDWARE INTERFACE

H

IR.......................................................................................................................................... 30

............................................................................................................................. 30

GENERAL PURPOSE I/O ..................................................................................................................... 32

NTRODUCTION

I

ESCRIPTION

D

EGISTERS

R

..........................................................................................................................................32

............................................................................................................................................32

..............................................................................................................................................34

DC ELECTRICAL CHARACTERISTICS............................................................................................... 36

A.C. TIMING .......................................................................................................................................... 38

LOCK AND RESET TIMING

C

EAD CYCLE TIMING (NON-MULTIPLEXED

R

EAD CYCLE TIMING (MULTIPLEXED

R

RITE CYCLE TIMING (NON-MULTIPLEXED

W

RITE CYCLE TIMING (MULTIPLEXED

W

......................................................................................................................... 38

)................................................................................................... 39

)........................................................................................................... 40

)................................................................................................. 41

)......................................................................................................... 42

2

EAD/WRITE CYCLE TIMING (MULTIPLEXED

R

INGLE TRANSFER MODE

S

URST TRANSFER MODE

B

DMA T

DMA T

IMING

IMING

)................................................................................................43

....................................................................................................... 44

........................................................................................................ 46

3

ARCHITECTURE

There are six basic architectural components in
the CAM35C44: the multihost CPU interface, the
IrCC 2.0, a clock generator, configuration
registers, power management, and general
purpose I/O (

FIGURE

The multihost CPU interface is capable of
supporting several bus configurations; including,
a non-multiplexed ISA-style address and data
bus, and a multiplexed address/data bus with
selectable read/write command options. The
multihost CPU interface includes support for
Hitachi and Mitsubishi microcontrollers.

1

).

nIOW/DSTRB

SD[7:0]/AD[7:0]

SA[1:0]/GPIO[4:3]

SA[4:2]/BS[2:0]

nCS
AEN

IOCHRDY

ASTRB

nNOWS

RESET_DRV

IRQ

DRQ

nDACK

TC

nIOR/RW

X1/CLK1 x2 PWRGD

CLOCK

GEN

MULTIHOST

CPU

INTERFACE

HS1 HS0

CONTROL

ADDRESS

CONFIGURATION

FIGURE 1 - CAM35C44 BLOCK DIAGRAM

The IrCC 2.0 is a multi-protocol serial
communications controller that incorporates an
ACE 16C550A UART and a Synchronous
Communications Engine (SCE). Refer to the
SMSC Infrared Communications Controller 2.0
specification for more information.

The clock generator provides connections for a
24MHz crystal or an external clock source. The
24MHz clock directly drives the ACE block. An
internal PLL is used for data rates above

115.2Kbps.
Power management in the CAM35C44 includes

various power down modes and an infrared
wake-up option. The general purpose I/O
interface provides generic I/O programming
capabilities.

VCC[2:1],VSS[3:1],

POWER

MGMT

VIO

POWER

GENERAL

PURPOSE

I/O

GPIO[2:0]

DATA

REGISTERS

IRCC 2.0

IRRX
IRTX

IRMODE/IRRX3

RXD/IRRX
TXD/IRTX

4

PIN CONFIGURATION

The CAM35C44 pin numbers are shown in
FIGURE 2. Functional descriptions per pin-

N/C

SA2/BS2

SA1/GP IO4

SA0/GP IO3

PWRG D

48

47

46

45

SA3/BS1

SA4/BS0

TXD/IRTX

IRTX

IRMODE/IRRX3

VIO

nIOR/RnW

nIOW/DSTRB

nNOWS

AEN

nCS

N/C

1

2

3

4

5

6

7

8

9

10

11

12

13

N/C

48 PI N T QFP

14

15

SD0/AD0

SD1/AD1

FIGURE 2 - CAM35C44 PIN CONFIGURATION

44

CAM35C44

16

17

SD2/AD2

SD3/AD3

group are shown in TABLE 1.

Note: The pin numbers in FIGURE 2 are subject
to change.

VSS

ASTRB

VDD

GPIO2

GPIO1

GPIO0

VSS

43

42

41

40

39

38

37

HS1

36

HS0

35

X2

34

X1/CLK1

33

IRRX

18

19

20

21

22

32

RXD/IRRX

31

TC

30

IOCHRDY

29

RESET_DRV

28

VDD

27

nDAC K

26

N/C

25

23

24

SD4/AD4

SD5/AD5

SD6/AD6

SD7/AD7

IRQ

VSS

DRQ

5

DESCRIPTION OF PIN FUNCTIONS

TABLE 1 - CAM35C44 PIN FUNCTION DESCRIPTION

NAME

ISA System Data Bus/
Multiplexed

Address/Data Bus
(Non-ISA)

ISA System Address
Bus (SA0 - SA1)/

General Purpose I/O
(GPIO3 - GPIO4)

ISA System Address
Bus (SA2 - SA4)/

Memory Block Selects
(BS0 - BS2)

Chip Select 1 nCS I The active low chip select input is

4

TOTAL

PINS

PROCESSOR/HOST INTERFACE (25)

8 SD[7:0]/AD[7:0] IO12 T his 8 bit bus is used to exchange

2 SA[1:0]/GPIO[4:3] I/IO12 The ISA system address bus is

3 SA[4:2]/BS[2:0] I The ISA system address bus is

SYMBOL

BUFFER

TYPE

DESCRIPTION

data with the host. The bus is bi­directional and can be configured
as either an ISA system data bus
or as a multiplexed address/data
bus (TABLE 3). These pins are in
a high-impedance state when not
in the output mode.

used to determine the I/O address
during read and write cycles.
These two ISA system address
bus pins are general purpose I/O
pins (TABLE 30) when a
multiplexed address/data host
interface type is selected (TABLE

3).

used to determine the I/O address
during read and write cycles.
These three ISA system address
bus pins are memory block select
pins (TABLE 10) when a
multiplexed address/data host
interface type is selected (TABLE

3).

a 32-byte address block decoder
when the ISA host interface type
is selected and a 256-byte page
decoder when a multiplexed
address/data host interface type is
selected (TABLE 3).

6

NAME

Address Enable 1 AEN I The active high Address Enable

ISA I/O Channel Ready 1 IOCHRDY OD12 IOCHRDY is pulled low to extend

Multiplex Mode
Address Strobe

No Wait State 1 nNOWS OD12 nNOWS can be enabled to be

ISA Reset Drive 1 RESET_DRV IS The RESET_DRV pin is active

IRQ

TOTAL

PINS

1 ASTRB I ASTRB is used to internally latch

1 IRQ

SYMBOL

BUFFER

TYPE

pin indicates DMA operations on
the host data bus. AEN must be
inactive to access the CAM35C44
registers and active during DMA
operations regardless of the
selected host interface type.

ISA I/O read/write commands.
Only SCE-driven functions in the
IrCC 2.0 can be enabled to use
IOCHRDY.

I/O addresses during read/write
cycles when a multiplexed
address/data host interface type is
selected (TABLE 3).

activated by IrCC 2.0 SCE-driven
functions to indicate that an
access cycle shorter than the
standard ISA I/O cycle can be
executed.

high and is used to reset the
CAM35C44 as described in the
appropriate sections in this
document. The configuration
registers are not affected by this
pin except where noted (TABLE

13). The RESET_DRV pin must
be valid for 500ns minimum.

OD12 The IRQ pin is forced active when

an interrupt is asserted. IRQ goes
inactive as soon as the source of
the interrupt has been cleared.
The active IRQ pin-state is
determined by the IRQ_LEV bit in
CR00 (see page 22).

DESCRIPTION

7

NAME

DMA Request 1 DRQ O12 The DRQ pin is forced active by

DMA Acknowledge 1 DACK I The DACK pin is forced active by

Terminal Count 1 TC I TC indicates that a DMA transfer

ISA I/O Read/
Non-ISA Read/Write

Control

ISA I/O Write/
Non-ISA R/W Data

Strobe

TOTAL

PINS

1 nIOR/RnW I The active low nIOR input is

1 nIOW/DSTRB I The active low nIOW input is

SYMBOL

BUFFER

TYPE

DESCRIPTION

the CAM35C44 when byte
transfers to the host using DMA
are required. DRQ goes inactive
when the transfer has been
completed. The active DRQ pin­state is determined by the
DRQ_LEV bit in CR01 (see page

22).

the host DMA controller to
acknowledge CAM35C44 transfer
requests. DACK goes inactive
following the transfer command.
The active DACK pin-state is
determined by the DAC_LEV bit in
CR01 (see page 23).

is complete. TC is only acknow­ledged when DACK is active.

issued by the host to execute I/O
read commands when an ISA
read/write-styled host interface
type is selected (TABLE 3). The
RnW input is used to determine
the I/O command type when a
non-ISA read/write-styled host
interface type is selected.

issued by the host to execute I/O
write commands when an ISA
read/write-styled host interface
type is selected (TABLE 3). The
DSTRB input is used to execute
the I/O command when a non-ISA
read/write-styled host interface
type is selected (FIGURE 5).

MISCELLANEOUS (12)

8

NAME

Clock Input (24MHz
CMOS Clock/Crystal)

Crystal Driver 1 X2 OCLK X2 is the 24M H z cry stal driver and

Host Interface Select 2 HS[1:0] IP The Host Interface Select bits

General Purpose I/O
(GPIO0 - GPIO2)

4

TOTAL

PINS

SYMBOL

BUFFER

TYPE

DESCRIPTION

1 X1/CLK1 ICLK X1/CLK is the input for either a

24MHz clock crystal or 24MH z
crystal oscillator source (see
section CLOCK GENERATOR on
page 12)

should be left unconnected if an
external clock source is used.

determine the host interface type.
These bits are static controls and
must remain stable during device
operation (see section
MULTIHOST CPU INTERFACE
on page 13).

3 GPIO[2:0] IO12 The general purpose I/O pins

provide a simple programmable
I/O interface. The state of a GPIO
pin can be forced to the value
contained in the GPIO data
register or this register can reflect
the logical state of the GPIO pin
depending on values programmed
in GPIO direction and enable
registers (see section GENERAL
PURPOSE I/O on page 32).

9

NAME

Power Good 1 PWRGD IP This active high input indicates

No Connect 4 N/C - No internal connections are made

Infrared Rx3 1 IRRX I This is the infrared port receiver

Infrared Tx

1,2

1 IRTX O12PD This is the infrared port transmitter

Infrared Mode/IRRX31 1 IRMODE/IRRX3 O12/I This is the infrared port secondary

+3.3V Digital Supply
Voltage

I/O Interface Supply
Voltage

1

Ground 3 VSS Ground Supply

TOTAL

PINS

SYMBOL

BUFFER

TYPE

DESCRIPTION

that the positive supply voltage
VCC is valid. For normal device
operation, PWRGD must be
active. When PWRGD is inactive,
all device inputs are disconnected
and placed into a low power state;
all outputs are put into a high­impedance state.

Note: The
crystal oscillator pins are
unaffected by PWRGD

contents of all registers are
preserved as long as VCC has a
valid value. Output driver current
drain when PWRGD is inactive
drops to I

- standby current.

STDBY

The PWRGD input has an internal
30#A pull-up.

to these pins.

INFRARED INTERFACE (3)

input pin.

output pin.

receiver input channel or a
transceiver mode control pin,
depending on the state of the
transceiver module interface type
select ( T ABLE 27).

POWER PINS (6)

2 VCC Positive Supply Voltage

1 VIO Positive I/O Interface Supply

Voltage

. The

10

NAME

Receive Serial Data 2/

3

Infrared Rx

Transmit Serial Data
2/Infrared Tx

Note
Note
Note
Note

1,2

1

TX and MODE pins drive to VIO level.

2

TX defaults to zero even during POR.

3

RX pins are voltage tolerant to VIO level.

4

All GPIOs are VIO tolerant and back drive protected.

Buffer-Type Summary

The characteristics of the buffer types shown in TABLE 1 are summarized in TABLE 2.

BUFFER TYPE DESCRIPTION

IO12 Input/Output. 12mA sink; 6mA source

O12 Output. 12mA sink; 6mA source

OD12 Open Drain. 12mA sink

O12PD

ICLK Input to Crystal Oscillator Circuit (TTL levels)

OCLK Output to External Crystal

I Input TTL Compatible.
IP
IS Input with Schmitt Trigger.

TOTAL

PINS

SERIAL PORT INTERFACE (2)

1 RXD/IRRX I This is the receiver input pin for

1 TXD/IRTX O12PD This is the transmitter output pin

TABLE 2 - CAM35C44 BUFFER-TYPE SUMMARY

Output. 12mA sink; 6mA source; 30#A Pulldown @ Tristate

Input TTL Compatible with 30#A Pullup

SYMBOL

BUFFER

TYPE

DESCRIPTION

the UART COM port or an
alternate infrared port receiver
input.

for the UART COM port or an
alternate infrared port transmitter
output.

11

CLOCK GENERATOR

An internal 3.3v crystal oscillator or an external
oscillator source is required for the CAM35C44
(FIGURE 3). The crystal/clock pins and buffer
types are shown in TABLE 1.

The X1/CLK1 and X2 pins provide an external
connection for a parallel resonant 24MHz crystal.
Configuration register CR08 bit 5, INT_OSC,
must be set to “1” to configure the internal
oscillator for this arrangement (see the section
CRO8 - Power Control on page 27).

An external CMOS compatible oscillator is
required if a 24MHz crystal is not used. In this
case INT_OSC must be set to “0”.

FIGURE 3 - EXAMPLE 24MHz OSCILLATOR CIRCUIT

CAM35C44

The X2 pin is the 24MHz crystal driver and
should not be used to drive any other device.
This pin should be left unconnected if an
external clock is used and INT_OSC is “0”.

The 24MHz crystal can be used to directly drive
the ACE block. This saves power when

115.2Kbps or slower data transfers are required
because the PLL and SCE block do not need to
be powered. See TABLE 25 and the section
CRO8 - Power Control on page 27.

X1/CLK1 X2

24MHz CRYSTAL

12

MULTIHOST CPU INTERFACE

The CAM35C44 multihost CPU interface is
capable of supporting three bus configurations;
including, 1) an ISA-style address and data bus,

2) a multiplexed address/data bus with ISA-style
read/write commands like the example shown in
(FIGURE 4, and 3) a multiplexed address/data

FIGURE 4 - NEC UPD781C1X READ CYCLE

bus with a read/write select and data strobe like
the example shown in FIGURE 5.

The CPU interface type as well as the type­specific multiplexing of the processor/host
interface pins (TABLE 1) is controlled by the
Host Interface Select pins.

AB[15:8]

AB[7:0]

ADDR7-ADDR

ADDR15-ADDR

0

8

Data In

ADDR STB

nRD

nWR

AB[15:8]

AB[7:0]

ADDR7-ADD R

ADDR15-ADD R

0

8

Data In

ADDR STB

R/nW

DATA STB

FIGURE 5 - HITACHI HD63P01M1 READ CYCLE

13

Host Interface Select

The Host Interface Select pins HS[1:0] (TABLE

1) determine the host interface type.

TABLE 3 - HOST INTERFACE ENCODING

HOST INTERFACE

SELECT

HS1

0 0 Reserved
0 1 ISA
1 0 MULTIPLEXED ADDRESS/DATA, Non-ISA

1 1 MULTIPLEXED ADDRESS/DATA,

Host Interface Pin Multiplexing

Pin multiplexing for the processor/host interface
(TABLE 1) is controlled by the Host Interface
Select pins HS[1:0].

System Data Bus

PIN NAME

SD[7:0] 0 0 NOT DEFINED
0 1 SD[7:0]
1 0 AD[7:0]
1 1 AD[7:0]

HS0

TABLE 4 - SD[7:0] PIN MULTIPLEXING

MUX CONTROLS

HS1

Read/Write (FIGURE 5)
ISA Read/Write (FIGURE 4)

HS0

The encoding for these bits is shown in TABLE

3. The Host Interface Select pins are static
controls and must remain stable during device
operation.

HOST INTERFACE TYPE

ISA signals that are not multiplexed, like
IOCHRDY and nNOWS, remain operative
regardless of the state of the Host Interface
Select bits.

The following tables describe processor/host
interface multiplexing per pin or per pin group.

SELECTED FUNCTION

14

ISA Address Bus SA0 - SA1

TABLE 5 - SA[1:0] PIN MULTIPLEXING

PIN NAME

SA[1:0] 0 0 NOT DEFINED
0 1 SA[1:0]
1 0 GPIO[4:3]
1 1 GPIO[4:3]

ISA Address Bus SA2 - SA4

PIN NAME

SA[4:2] 0 0 NOT DEFINED
0 1 SA[4:2]
1 0 BS[2:0]
1 1 BS[2:0]

ISA nIOR

PIN NAME

nIOR 0 0 NOT DEFINED
0 1 nIOR
1 0 R/nW
1 1 nIOR

ISA nIOW

PIN NAME

nIOW 0 0 NOT DEFINED
0 1 nIOW
1 0 DSTRB
1 1 nIOW

MUX CONTROLS

HS1

TABLE 6 - SA[4:2] PIN MULTIPLEXING
MUX CONTROLS

HS1

TABLE 7 - nIOR PIN MULTIPLEXING

MUX CONTROLS

HS1

TABLE 8 - nIOW PIN MULTIPLEXING

MUX CONTROLS

HS1

HS0

HS0

HS0

HS0

SELECTED FUNCTION

SELECTED FUNCTION

SELECTED FUNCTION

SELECTED FUNCTION

15

REGISTER ADDRESS MAP

Register addressing in the CAM35C44 is fixed
and requires a 32-byte memory block. Typically,
register addressing is accomplished with a 5 bit
address bus and a 1 bit chip select.

TABLE 9 describes the mapping for the four
register banks in the CAM35C44 address

TABLE 9 - CAM35C44 REGISTER MAP

8-BYTE

ADDRESS

BANK

BANK

SELECT

SA4

BITS

SA3

ADDRESS RANGE

SA[4:0]

0 0 0 0x00 - 0x07 CONFIGURATION
1 0 1 0x08 - 0x0F GPIO
2 1 0 0x10 - 0x17 ACE
3 1 1 0x18 - 0x1F SCE

1

Note

Address Enable (AEN) must be low to access the CAM35C44 registers regardless of the state

of the Host Interface Select bits.

Non-Multiplexed (ISA) Addressing

As shown in TABLE 9 five address bits SA[4:0]
and a chip select nCS are required to access the
CAM35C44 run-time and configuration registers.

In ISA mode, five bits of the ISA System Address
bus SA[4:0] determine the register

space, CONFIGURATION, GPIO, ACE and
SCE, that are required for device configuration
and run-time control.

The external address pins that are responsible
for register addressing will depend on the Host
Interface Select bits (see section MULTIHOST
CPU INTERFACE on page 13).

1

address, while nCS decodes the 32-byte
address block. Note: address block decoding
must be done externally.

The Block Select bits BS[2:0] and two of the
general purpose I/Os GPIO[4:3] are unavailable
in ISA mode.

REGISTER BANK DECODING

16

Multiplexed Addressing

When multiplexed address modes are selected,
i.e. HS[1:0] = 02H or 03H (TABLE 3), register
addresses are decoded from the Multiplexed
Address/Data Bus AD[7:0], the Block Select bits
BS[2:0] and the chip select nCS pin.

In the multiplexed addressing modes the 5 low­order bits of the Multiplexed Address/Data Bus
AD[4:0] determine the register address while the
Block Select bits BS[2:0] qualify the

TABLE 10 - EXAMPLE MULTIPLEXED ADDRESS DECODING

256-BYTE

ADDRESS

PAGE

nCS BS2 BS1 BS0 AD[7:0]

1 0 0 1 XXH No Decode: Invalid Page
0 0 0 1 20H Decode Configuration Bank Index

0 0 0 1 00H No Decode: Invalid Block

32-BYTE ADDRESS

BLOCK

MULTIPLEX

ADDR/DATA BUS

three high-order Multiplexed Address/Data Bus
bits, AD[7:5]; i.e., BS[2:0] decodes which of eight
32-byte blocks is selected in the 256-byte page
decoded by nCS. Note: page address decoding
must be done externally.

For example, TABLE 10 illustrates that if BS[2:0]
= 01H, nCS = 0 (active), and AD[7:0] = 20H, the
Index Register in the Configuration Bank has
been selected.

Two extra GPIO pins GPIO[4:3] are available in
the multiplexed address modes.

DESCRIPTION

Register (TABLE 12)

17

CONFIGURATION

The CAM35C44 configuration registers are used
to program selectable chip-level device options
(TABLE 13).

The configuration registers can only be
programmed through the configuration access
ports that appear when the chip is placed into
the configuration state.

Configuration register programming typically
follows this sequence:

1. Enter the Configuration State,

2. Program the Configuration
Register(s),

3. Exit the Configuration State.

TABLE 11 - CONFIGURATION ACCESS PORTS

PORT NAME ADDRESS DIRECTION

CONFIG PORT BANK 0, ADDRESS 03 WRITE
INDEX PORT BANK 0, ADDRESS 03 READ/WRITE
DATA PORT BANK 0, ADDRESS 13 READ/WRITE1

1

Note

The INDEX and DATA ports are active only when the CAM35C44 is in the configuration

state.

2

Note

The INDEX PORT is only readable in the configuration state.

3

Note

The CAM35C44 register banks are described in section REGISTER ADDRESS MAP on
page 16. The register addresses in the CAM35C44 configuration bank are shown in
TABLE 12.

If enabled, logical devices in the CAM35C44 will
operate normally in the configuration state.

Configuration Access Ports

The configuration access ports are the config
port, the index port, and the data port (TABLE

11).
The configuration access ports are the only

addressable registers in the CAM35C44
configuration bank (TABLE 12).

The index port and the data port are only active
in the configuration state.

1,2

18

Configuration State

Logical devices in the CAM35C44 can operate in
the run state and/or the configuration state. After
power up the CAM35C44 is in the run state, by
default.

To program the configuration registers the
configuration state must be explicitly enabled.

Entering the Configuration State

To enter the configuration state, a configuration
access key must be written to the config port.
The configuration access key is one byte of 55H
data.

Once the configuration access key has been
written to the config port, the CAM35C44
automatically activates the configuration access
ports and enters the configuration state.

Configuration Select Register

The Configuration Select Register (CSR) is
located at the index port address and must be
initialized with the configuration register index
before the register can be accessed using the
data port.

The CSR can only be accessed when the
CAM35C44 is in the configuration state.

Configuration Register Programming

The CAM35C44 contains ten configuration
registers CR00-CR09. After the CAM35C44
enters the configuration state, the configuration
registers are programmed by first writing the
register index number (00 - 09) to the
configuration select register (CSR) and then
writing or reading the configuration register
contents through the data port.

Configuration register access remains enabled
until the configuration state is explicitly exited.

Exiting the Configuration State

To exit the configuration state one byte of AAH
data must be written to the config port.

Once AAH has been written to the config port,
the CAM35C44 automatically deactivates the
configuration access ports and enters the run
state. In the run state, configuration register
access cannot occur until the configuration state
is explicitly re-enabled.

19

Programming Example

The following Intel 8086 assembly language instructions illustrate CAM35C44 configuration register
programming. In this example, the config port is located at address 3F0H.

;-----------------------------.
; ENTER CONFIGURATION STATE |

;-----------------------------’
MOV DX,3F0H
MOV AX,055H
OUT DX,AL
;-----------------------------.
; CONFIGURE REGISTERS CR0-CRx |

;-----------------------------’
MOV DX,3F0H
MOV AL,00H
OUT DX,AL ;Point to CR0
MOV DX,3F1H
MOV AL,3FH
OUT DX,AL ;Update CR0
;
MOV DX,3F0H
MOV AL,01H
OUT DX,AL ;Point to CR1
MOV DX,3F1H
MOV AL,9FH
OUT DX,AL ;Update CR1
;
; Repeat for all CRx registers
;
;-----------------------------.
; EXIT CONFIGURATION STATE |

;-----------------------------’
MOV DX,3F0H
MOV AX,AAH
OUT DX,AL

20

Configuration Registers
Introduction

The configuration registers (TABLE 13) are set
to their default values at power up and are not
affected by RESET, except where noted in the
register descriptions that follow.

Configuration register bits that are not needed in
the CAM35C44 are marked RESERVED in the
sections below. RESERVED bits cannot be
written and return “0” when read.

TABLE 12 - CONFIGURATION REGISTER BANK

ADDRESS DEFAULT REGISTER NAME

0x00 0x00 Config/Index Register
0x01 0x00 Data Register

0x00 RESERVED

RESET

DEFAULT

Description

CR

INDEX

0x00 0x00 0x00 IRQ CONTROL
0x01 0x00 0x00 DMA CONTROL
0x02 0x02 n/a INFRARED OPTION
0x03 0x01 n/a INFRARED CONTROL B
0x04 0x00 n/a TEST CONTROL A
0x05 0x00 n/a
0x06 0x00 n/a
0x07 0x03 n/a IR HALF DUPLEX TIME-OUT
0x08 0x00 0x00 POWER CONTROL
0x09 0x00 n/a TEST CONTROL B

0x02

.
.
.

0x07

TABLE 13 - CONFIGURATION REGISTERS

POR

DEFAULT

Configuration Register references are in hex;
e.g., CRC0.3 means

Bit

0xC0,

Configuration Bank Addressing

The CONFIGURATION register bank is defined
as the first eight addresses in the CAM35C44
memory map (see section REGISTER
ADDRESS MAP on page 16).

TABLE 12 summarizes the contents of the
CONFIGURATION bank. The Index and Data
registers access the configuration registers
(TABLE 13) as described above.

SOFTWARE SELECT A
SOFTWARE SELECT B

0x03.

REGISTER NAME

Configuration Register

21

CR00 - IRQ Control

The IRQ Control register CR00 determines the
IRQ pin polarity and enables the configuration
register locking feature.

CR00 can only be accessed in the

TABLE 14 - IRQ CONTROL REGISTER

CR00 R/W RESERVED LOCK RES IRQ_LEV 0x00

IRQ_LEV, Bit 0

The IRQ_LEV bit D0 determines the active state
of the IRQ output pin (TABLE 1). If IRQ_LEV is
“0” (default), the IRQ pin is active low. If
IRQ_LEV is “1”, the IRQ pin is active high.

LOCK, Bit 2

The LOCK bit D2 selects configuration register
locking. “Locked” means configuration registers
can be read but cannot be written, except for the
IRCC Legacy Controls like the IR HALF
DUPLEX TIME-OUT that can be written through
the SCE Registers and appear in the chip-level
configuration registers regardless of the state of
the LOCK bit.

If LOCK is “0” (default), the configuration
registers are unlocked. If LOCK is “1”, the
configuration registers are locked.

CR01 R/W RESERVED DAC_LEV DREQ_LEV 0x00

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

TABLE 15 - DMA CONTROL REGISTER (CR01)

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

configuration state and only after the CSR has
been initialized to 00H. The default value of this
register after power up is 00H (TABLE 14).

Bits[7:3, 1] in the IRQ Control register are
RESERVED.

Note: once the LOCK bit is set to “1” the
configuration registers are permanently locked.
The LOCK bit can only be reset to “0” by a hard­reset or a power-on-reset; i.e., the configuration
registers cannot be changed until either a hard­reset or power-on-reset occur.

CR01 - DMA Control

The DMA Control register CR01 determines the
DRQ and DACK pin polarity (TABLE 1).

CR01 can only be accessed in the configuration
state and only after the CSR has been initialized
to 01H. The default value of this register after
power up is 00H (TABLE 15).

Bits[7:2] in the DMA Control register are
RESERVED.

22

DRQ_LEV, Bit 0

The DRQ_LEV bit D0 determines the active
state of the DMA Request (DRQ) output pin
(TABLE 1).

If DRQ_LEV is “0” (default), the DRQ pin is
active low. If DRQ_LEV is “1”, the DRQ pin is
active high.

DAC_LEV, Bit 1

The DAC_LEV bit D1 determines the active state
of the DMA Acknowledge (DACK) input pin
(TABLE 1).

If DAC_LEV is “0” (default), the DACK pin is
active low. If DAC_LEV is “1”, the DACK pin is
active high.

TABLE 16 - INFRARED OPTION REGISTER

CR02 R/W

RCV_POL, Bit 0

The RCV_POL bit D0 defines the active state for
the infrared port receive pins.

If RCV_POL is “0” (default), the IRRX pin is
active low. If RCV_POL is “1”, the IRRX pin is
active high.

The RCV_POL pin has no affect when the port is
configured as a 16C550A UART (see section
IR_MODE, Bits 3 - 5 on page 24).

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

RES.

IR_

MODE2

IR_

MODE1

CR02 - Infrared Option

The Infrared Option register CR02 determines
the infrared port transmit and receive pin
polarity, the port duplex mode, and the infrared
port protocol.

The controls in the Infrared Option register are
also duplicated in the IrCC 2.0 SCE
Configuration Register A. These controls are
arranged such that the last write from either
source determines the current control state and
is visible in both registers.

CR02 can only be accessed in the configuration
state and only after the CSR has been initialized
to 02H. The default value of this register after
power up is 02H (TABLE 16).

Bits[7:6] in the Infrared Option register are
RESERVED.

IR_

MODE0

HALF

DUPLEX

XMT_

POL

RCV_

POL

0x02

XMT_POL, Bit 1

The XMT_POL bit D1 defines the active state for
the infrared port transmit pins.

If XMT_POL is “0”, the IRTX pin is active low. If
XMT_POL is “1” (default), the IRTX pin is active
high.

The XMT_POL pin has no affect when the port is
configured as a 16C550A UART (see section
IR_MODE, Bits 3 - 5 on page 24).

23

HALF DUPLEX, Bit 2

When the HALF DUPLEX bit D2 is “0” (default),
the 16C550A UART in the IrCC 2.0 is in full
duplex mode. Full duplex mode has no effect on
the IrCC 2.0 SCE.

When the HALF DUPLEX bit is “1”, the IrCC 2.0
is in half duplex mode. Half duplex mode is
typically required for all infrared transactions.

In half duplex mode, the IR Half Duplex Time­Out will apply to IrCC 2.0 transmit/receive

TABLE 17 - CAM35C44 INFRARED PROTOCOL OPTIONS

IR_MODE[2:0]

D5 D4 D3 MODE

0 0 0 COM 16C550A UART (Default)
0 0 1 IrDA SIR-A Up to 115.2Kbps, Variable 3/16ths Pulse
0 1 0 ASK IR 500KHz Carrier, Amplitude Shift Keyed IR
0 1 1 IrDA SIR-B
1 0 0 IrDA HDLC 0.576Mbps and 1.152Mbps
1 0 1 IrDA 4PPM 4Mbps
1 1 0 CONSUMER Consumer (TV Remote) IR
1 1 1 RAW Direct IR Diode Control

CR03 - Infrared Control B

The Infrared Control B register CR03 configures
the infrared interface and COM port clock select.

CR03 can only be accessed in the

CR03 R/W RESERVED MIDI RESERVED HPMODE 0x01

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

TABLE 18 - IR CONTROL B REGISTER

direction mode changes (see section CR07 - IR
Half Duplex Time-Out on page 26). The IR Half
Duplex Time-Out does not apply to full duplex
mode.

IR_MODE, Bits 3 - 5

The IR_MODE bits D3 - D5 select the active
IrCC 2.0 encoder/decoder. The default is COM
(TABLE 17).

The IR_MODE bits are equivalent to the three
low-order Block Control bits in the IrCC 2.0 SCE
Configuration Register A.

DESCRIPTION

Up to 115.2Kbps, Fixed 1.6#s Pulse

configuration state and only after the CSR has
been initialized to 03H. The default value of this
register after power up is 01H (TABLE 18).

Bits[7:5,3:1] in the Infrared Control B register are
RESERVED.

24

HPMODE, Bit 0

The HPMODE bit D0 is used to configure the
transceiver type in the CAM35C44 infrared
interface (see FIGURE 6). When HPMODE is
“1” (default), the IRMODE/IRRX3 pin is
configured as an input (IRRX3) to support
transceiver types that require two receive
channels. When HPMODE is “0”, the
IRMODE/IRRX3 pin is configured as an output
(IRMODE) to support transceiver types that
require one receive channel and a mode control
pin.

MIDI, Bit 4

The MIDI bit D4 is the 16C550A UART clock
divider select. When MIDI is “0” (default), the
16C550A clock divider is configured to

TABLE 19 - TEST CONTROL A REGISTER

CR04 R/W IR_TEST[6:0] IR_LB 0x00

IR_LB, Bit 0

The IR_LB bit D0 enables serial loopback
testing, independent of the internal IrCC 2.0
loopback controls. When IR_LB is “1” the
transmit output is internally connected to the
receiver input. When IR_LB is “0” (default), the
transmit output is not connected to the receive
input and loopback testing is disabled.

IR_TEST[6:0], Bits 1 - 7

The IR_TEST[6:0] bits D1 - D7 control SMSC
internal test modes.

The IR_TEST[6:0] bits are “0” (default) for
normal operation.

When any of the IR_TEST[6:0] bits are “1”, an
SMSC internal test mode is activated. Note:
SMSC internal test modes are reserved for

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

generate the standard UART data rates up to

115.2Kbaud.
When MIDI is “1”, the 16C550A clock divider is

configured to generate UART data rates that are
compatible with the 31.25Kbaud ($1%) Musical
Instrument Digital Interface standard.

CR04 - Test Control A

The Test Control A register CR04 enables user­level serial loopback testing and SMSC internal
test modes.

CR04 can only be accessed in the configuration
state and only after the CSR has been initialized
to 04H. The default value of this register after
power up is 00H (TABLE 19).

SMSC use, only. Activating SMSC internal test
modes may produce undesired results.

CR05 - Software Select A

The Software Select A register CR05 is directly
connected to the read-only IrCC 2.0 Software
Select A register in SCE Register Block Three.
Writing to CR05 is the only way to revise the
contents of the Software Select A register.
CR05 can only be accessed in the configuration
state and only after the CSR has been initialized
to 05H. The default value of this register after
power up is 00H (TABLE 20).

25

TABLE 20 - SOFTWARE SELECT A REGISTER

CR05 R/W Software Select A 0x00

CR06 - Software Select B

The Software Select B register CR06 is directly
connected to the read-only IrCC 2.0 Software
Select B register in SCE Register Block Three.
Writing to CR06 is the only way

CR06 R/W Software Select B 0x00

CR07 - IR Half Duplex Time-Out

CR07 is the IR Half Duplex Time-Out register
(TABLE 22).

If the Half Duplex option is selected (see section
HALF DUPLEX, Bit 2 on page 24), the IR half
duplex time-out constrains the timing of
transmit/receive direction mode changes in the
IrCC 2.0. The IR half duplex time-out is started
as each IR message data bit is transferred and
prevents direction mode changes until the time­out expires. The timer is restarted whenever
new data is transferred in the current direction
mode.

For example, in an SIR mode if data is loaded
into the transmit buffer while a character is being
received, the transmission will not start

CR07 R/W IR HALF DUPLEX TIME-OUT 0x03

D7 D6 D5 D4 D3

to revise the contents of the Software Select B
register. CR06 can only be accessed in the
configuration state and only after the CSR has
been initialized to 06H. The default value of this
register after power up is 00H (TABLE 21).

TABLE 21 - SOFTWARE SELECT B REGISTER

D7 D6 D5 D4

D3

until the last bit has been received and the time­out expires. If the start bit of another character
is received during this time-out, the timer is
restarted after the new character is received.

The IRCC block i n the CAM35C44 also incl udes
an 8 bit IR half duplex time-out register, like
CR07, in SCE Register Block 5. These two
registers behave like the other IRCC legacy
controls where either source uniformly updates
the value of both registers when either register is
explicitly written using IOW or following a device­level POR. IRCC software resets d o not affect
these registers.

The IR half duplex time-out is programmable
from 0 to 25.5ms in 100#s increments, as
follows:

IR HALF DUPLEX TIME-OUT = (CR07) x 100

TABLE 22 - IR HALF DUPLEX TIME-OUT REGISTER
D7

D6

D5

D4

D2 D1 D0 DEFAULT

D2

D3

D1

D2

####

s

D1

D0

D0 DEFAULT

DEFAUL

T

26

CR08 - Power Control

The Power Control register CR08 contains the
power control enables to select the various
CAM35C44 power states (TABLE 25) and also
includes a bit to configure the system clock

TABLE 23 - POWER CONTROL REGISTER

CR08 R/W

OSC_ON, Bit 0

The OSC_ON bit D0 determines the power state
for CAM35C44 clock generator, independent of
the clock source (see section INT_OSC, Bit 5 on
page 28). When OSC_ON is “0” (default), the
clock generator is powered down. When
OSC_ON is “1”, the clock generator is running.

ACE_ON, Bit 1

The ACE_ON bit D1 along with the AUTO_PWR
bit D4 determines the power state for IrCC 2.0
ACE UART. When ACE_ON is “0” (default), the
UART is powered down, regardless of the state
of AUTO_PWR; i.e., when ACE_ON is “0”,
UART wake-up events are disabled (see section
AUTO_PWR, Bit 4). When ACE_ON is “1”, the
UART is active.

PLL_ON, Bit 2

The PLL_ON bit D2 determines the power state
for the PLL clock multiplier. The PLL is required
for IrDA transfers above 115.2Kbps. When
PLL_ON is “0” (default), the PLL is powered
down. When PLL_ON is “1”, the PLL is running.

D7 D6 D5 D4 D3 D2 D1 D0

RES

INT_
OSC

AUTO_

PWR

source. CR08 can only be accessed in the
configuration state and only after the CSR has
been initialized to 08H. The default value of this
register after power up is 00H (TABLE 23).
Bits[7:6] in the Power Control register are
RESERVED.

Default

SCE_

ON

PLL_

ON

ACE_ON OSC_ON 0x00

SCE_ON, Bit 3

The SCE_ON bit D3 determines the power state
for the IrCC 2.0 SCE. The SCE is required for
IrDA transfers above 115.2Kbps and for all
Consumer IR transactions. When SCE_ON is
“0” (default), the SCE is powered down. When
SCE_ON is “1”, the SCE is active.

AUTO_PWR, Bit 4

The AUTO_PWR bit D4 along with the ACE_ON
bit D1 selects the auto power down state of the
ACE UART (TABLE 24). When AUTO_PWR is
“0” (default), the ACE auto power down state is
disabled and the ACE UART power state is
controlled solely by the ACE_ON bit (see section
ACE_ON, Bit 1 on page 27). Note: If the ACE
auto power state is disabled the ring indicator
(nRI) and the RXD power-on wake-up events are
disabled. When AUTO_PWR is “1” and
ACE_ON is “1”, the ACE auto power down state
is enabled and the following power management
events are possible.

27

Transmitter Auto Power Down

The UART transmitter is powered down from the
auto power down state when the transmit buffer
and transmit shift registers are empty.

Receiver Auto Power Down

The UART receiver is powered down from the
auto power state when the receive FIFO is
empty and the receiver is waiting for a start bit.

TABLE 24 - ACE UART POWER STATES

ACE_ON

(D1)

0 X ACE POWER OFF
1 0 ACE POWER ON
1 1 ACE AUTO POWER DOWN

INT_OSC, Bit 5

The INT_ OSC bit D5 selects the clock source
for the CAM35C44 clock generator (see section
CLOCK GENERATOR on page 12).

AUTO_PWR

(D4)

Ring Indicator Auto Power Down

When the UART is powered down from the auto
power state, a Ring Indicator interrupt can occur
on active transitions of the Ring Indicator input
nRI.

Exit Auto Power Down

The transmitter exits the auto power down state
on a write to the transmit buffer. The receiver
exits the auto power down state when the
receiver input RXD changes state.

DESCRIPTION

When INT_OSC is “0” (default), the clock
generator is driven by an external clock source.
When INT_OSC is “1”, the clock generator is
driven by the internal crystal oscillator.

28

TABLE 25 - EXAMPLE POWER CONSUMPTION VS. POWER CONTROL ENABLES

CR08[3:0]

D3 D2 D1 D0

0 0 0 0

0 0 0 1
0 0 1 1
0 1 1 1
1 1 1 1

1

Note

: The 24MHz crystal oscillator directly driving the ACE block enables data transfers up to

115.2Kbps.

2

Note

: The PLL driving the SCE block enables data transfers up to 4Mbps.

3

Note

: PW RGD does not stop the crystal from oscillating if OSC_ON, D0 in configuration register

CR08, is “1”.

4

Note

: PWRGD i s “0”.

5

Note

: PWRGD i s “1”.

CR09 - Test Control B

The IR_TEST[14:7] bits D0 - D7 in the Test
Control B register enable SMSC internal test
modes. CR09 can only be accessed in the
configuration state and only after the CSR has
been initialized to 09H. The default value of this
register after power up is 00H (TABLE 26). The
IR_TEST[14:7] bits are “0” (default)

CR09 R/W IR_TEST[14:7] 0x00

POWER

CONSUMPTION

(ICC)

TYP MAX

1

#

2

#

(Note

500

A4
A5

#

3

A

)

2.5

#

5

#

(Note

1mA

A4

A5

3

)

1mA 2mA

1.6mA 3mA
6mA 8mA

CLOCK

GENERATOR BLOCK

ACE

1

PLL BLOCK2

OFF OFF OFF OFF

RUNNING OFF OFF OFF
RUNNING ON OFF OFF
RUNNING ON
RUNNING ON

RUNNING
RUNNING

for normal operation. When any of the
IR_TEST[14:7] bits are “1”, an SMSC internal
test mode is activated. Note: SMSC internal test
modes are reserved for SMSC use, only.
Activating SMSC internal test modes may
produce undesired results.

TABLE 26 - TEST CONTROL B REGISTER

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

SCE

OFF

ON

29

INFRARED INTERFACE

The CAM35C44 infrared interface can support
various infrared protocols and transceiver
configurations. For more information consult the
SMSC Infrared Communication Controller (IrCC

2.0) specification.

IrDA SIR/FIR

IrDA SIR (v1.0) specifies asynchronous serial
communication at baud rates up to 115.2kbps.
Each byte is sent serially LSB first beginning
with a zero value start bit. A zero is signaled by
sending a single infrared pulse at the beginning
of the serial bit time. A one is signaled by the
absence of an infrared pulse during the bit time.
IrDA FIR (v1.1) includes IrDA v1.0 SIR and
additionally specifies synchronous serial
communications at data rates up to 4Mbps.
Data is transferred LSB first in packets that can
be up to 2048 bits in length. IrDA v1.1 includes
.576Mbps and 1.152Mbps data rates using an
encoding scheme that is similar to SIR. The
4Mbps data rate uses a pulse position
modulation (PPM) technique.

ASKIR

The ASKIR infrared protocol allows
asynchronous amplitude shift keyed serial
communication at baud rates up to 19.2kbps.

TABLE 27 - TRANSCEIVER MODULE INTERFACE TYPE SELECT

HP MODE (CR03.0) FUNCTION

0 IR Mode
1 IRRX3

Each byte is sent serially LSB first beginning
with a zero value start bit. A zero is signaled by
sending a 500kHz carrier waveform for the
duration of the serial bit time. A one is signaled
by the absence of carrier during the bit time.

Consumer IR

The CAM35C44 Consumer IR interface is a
general-purpose synchronous amplitude shift
keyed encoder/decoder with programmable
carrier and bit-cell rates that can emulate many
popular TV Remote encoding formats; including,
38kHz PPM, PWM and RC-5. Each bit is sent
serially LSB first. The carrier frequency is
programmable from 1.6MHz to 6.25kHz. The
bit-cell rate range is 100kHz to 390Hz.

Hardware Interface

The CAM35C44 IR hardware interface is shown
in FIGURE 6. This interface supports two types
of IR transceiver modules. One interface type
requires a mode pin (IR Mode) to select the data
rate, while the other interface type requires a
second Rx data pin (IRRX3). The transceiver
interface type is selected with the HPMODE bit
D0 in CR03 as shown in TABLE 27 (see section
HPMODE, Bit 0 on page 25).

30

(

)

The FAST bit in FIGURE 6 is used to select
between an SIR mode and FIR mode receiver,
regardless of the transceiver type. If FAST is

TABLE 28 - IR RX DATA PIN SELECTION

CONTROL SIGNALS

FAST HPMODE RX1 RX2

0 X RXD2 IRRX2
X 0 RXD2 IRRX2
1 1 IR MODE/IRRX3 IR MODE/IRRX3

FIGURE 6 - IR INTERFACE BLOCK DIAGRAM

“1”, the FIR mode receiver is selected; if FAST is
“0”, the SIR mode receiver is selected (TABLE

28).

INPUTS

RAW

TV

ASK

SIR

COM

IR

RX1

RX2

TX1

0

1

TX2

0

1

TXD2

RXD2

IRTX

IRRX

FIR

aux

COM

G.P. DATA

FAST BIT

FAST

IRMODE

HPMODE

IRMODE
/IRRX3

IrCC 2.0

31

GENERAL PURPOSE I/O

Introduction

The CAM35C44 can support up to 5 general
purpose I/O pins, GPIO[4:0] (TABLE 1). The
number of available general purpose I/O pins

TABLE 29 - GPIO REGISTER BANK MAP

BANK ADDRESS DEFAULT REGISTER NAME

BANK 1 0x00 0x00 GPIOA Enable Register

(GPIO) 0x01 0x00 RESERVED

0x02 0x00 GPIOA Data Register
0x03 0x00 RESERVED
0x04 0x00 GPIOA Direction Register
0x05 0x00 RESERVED
0x06 0x00 RESERVED
0x07 0x00 RESERVED

Description

The state of a GPIO pin can be forced to the
value contained its data register, depending on
the state of its direction and enable bits. For
example, when a GPIO pin is configured as an
output the data register contains a “1” and the
enable bit is active, the GPIO pin will be driven
high. When a GPIO pin is configured as an input
and the enable is active, the value in the data
register will reflect the state of the

depends upon the Host Interface Select bits (see
the section MULTIHOST CPU INTERFACE on
page 13). The general purpose I/O pins are
controlled by the GPIO registers contained in
Bank 1 of the CAM35C44 memory map (see the
section REGISTER ADDRESS MAP on page

16). TABLE 29 summarizes the contents of the
GPIO register bank.

pin. When a GPIO pin is configured as an input
and the enable is inactive, state changes at the
pin are not reflected in the data register. W hen
a GPIO pin is configured as an output and the
enable is inactive, changes in the data register
do not affect the pin. TABLE 12 summarizes the
GPIO pin behavior described above. FIGURE 7
illustrates GPIO pin functionality. Note: FIGURE
7 is for illustration purposes only and is not
intended to suggest specific implementation
details.

32

TABLE 30 - GPIO FUNCTIONAL DESCRIPTION

GPx

ENABLE

1

1 1 OUTPUT READ CURRENT

WRITE NEW VALUE Output pin is active (driven),

1 0 INPUT READ CURRENT

WRITE NO EFFECT Input pin is active, writes

0 1 INPUT READ LAST VALUE Output pin is floating, reads

WRITE NEW VALUE Output pin is floating, writes

0 0 INPUT READ LAST VALUE Input pin is disabled, reads

WRITE NO EFFECT Input pin is disabled, writes

Note1 This represents a GPIO Enable register bit. The GPIO Enable register is GP00 (see section
GPIOA Enable Register on page 34).

2

Note

This represents a GPIO Direction register bit. The GPIO Direction register is GP04 (see

section GPIOA Direction Register on page 35).

3

Note

This represents a GPIO Data register bit. The GPIO Data register is GP02 (see section

GPIOA Data Register on page 35).

GPx

OUT2

GPIOx PIN

DIRECTION

I/O

COMMAND

GPx

DATA3

VALUE

VALUE

DESCRIPTION

Output pin is active (driven),
reads return last write.

writes update data register.
Input pin is active, reads
return the current state of the
pin.

have no effect.
return last active state.
update data register.
return last enabled read

state.
have no effect.

33

GPx_OUT

GPx_EN

GPx_DAT

DQ

D-TYPE

GPx_nIOW

CLK

GPx_nIOR

FIGURE 7 - GENERAL PURPOSE I/O BLOCK DIAGRAM

Note:

This figure is for illustration purposes only and is not intended to suggest specific

implementation details)

Registers

GPIOA Enable Register

The GPIOA Enable register GP00 contains the
enable bits for the five general purpose I/O pins
(TABLE 31). When any of the GPx_EN bits are
“1”, the associated general purpose I/O pin is
enabled. When any of the GPx_EN bits are “0”,
the associated general purpose

GP00 R/W

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

RESERVED

TABLE 31 - GPIOA ENABLE REGISTER

GP4_

EN

GP3_

EN

1

GPIOx

DQ

TRANS-

PARENT

0

G

I/O pin is disabled. The affects of the GPx_EN
bits are summarized in TABLE 30. GP00 can be
accessed both in the configuration state and the
run state (see section REGISTER ADDRESS
MAP on page 16 and TABLE 29). The default
value of the GPIOA Enable register after power
up is 00H. Bits[7:5] in the GPIOA Enable
register are RESERVED.

GP2_

EN

GP1_

EN

GP0_

EN

0x00

34

GPIOA Data Register

The GPIOA Data register GP02 contains the
data bits for the five general purpose I/O pins
(TABLE 32). The state of a GPIO pin can be
forced to the value contained its data register, or
the value in the data register can reflect the state
of the pin, depending on the state of the
direction and enable bits. The affects of the

TABLE 32 - GPIOA DATA REGISTER

GP02 R/W

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

RESERVED

GP4_

DAT

GPIOA Direction Register

The GPIOA Direction register GP04 contains the
direction bits for the five general purpose I/O
pins (TABLE 33). The direction of a GPIO pin
depends upon the state of the direction bit and
the enable bit, but typically if the direction bit is
“1” the GPIO pin is an output; if the direction bit
is “0” the GPIO pin is an input.

TABLE 33 - GPIOA DIRECTION REGISTER

GP04 R/W

D7 D6 D5 D4 D3 D2 D1 D0 DEFAULT

RESERVED

GP4_

OUT

GP3_

OUT

GPx_DAT bits are summarized in TABLE 30.
GP02 can be accessed both in the configuration
state and the run state (see section REGISTER
ADDRESS MAP on page 16 and TABLE 29).
The default value of the GPIOA Data register
after power up is 00H. Bits[7:5] in the GPIOA
Data register are RESERVED.

GP3_

DAT

GP2_

DAT

GP1_

DAT

GP0_

DAT

0x00

The affects of the GPx_OUT bits are
summarized in TABLE 33. GP04 can be
accessed both in the configuration state and the
run state (see section REGISTER ADDRESS
MAP on page 16 and TABLE 29). The default
value of the GPIOA Direction register after
power up is 00H. Bits[7:5] in the GPIOA
Direction register are RESERVED.

GP2_

OUT

GP1_

OUT

GP0_

OUT

0x00

35

DC ELECTRICAL CHARACTERISTICS

(TA = 0°C - 70°C4, Vcc = +3.3 V ± 10%)

Note: Numbers appearing in parentheses represent the values for TXD/IRTX, IRTX,

IRMODE/IRRX3 when VIO is 5 Volt.

PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS

I Type Input Buffer

Low Input Level
High Input Level

IS Type Input Buffer

Low Input Level
High Input Level
Schmitt Trigger Hysteresis

I

Input Buffer

CLK

Low Input Level
High Input Level

Input Leakage

(All I and IS buffers except
PWRGD)

Low Input Leakage
High Input Leakage

Input Current

PWRGD

IO12 Type Buffer

Low Output Level
High Output Level
Output Leakage

V
V
V

V
V

V
V

HYS

ILCK

IHCK

I

I

IOH

V
V

I

OL

ILI

IHI

ILIS

IHIS

IL

IH

OL

OH

0.8

2.0

2.2
250

0.8

0.4

2.8

-10

-10

2.4

-10

+10
+10

75

150

0.4

+10

V
V

V
V

mV

V
V

µA
µA

µA V

V
V

µA

TTL Levels

Schmitt Trigger
Schmitt Trigger

V

= 0

IN

V

= Vcc

IN

= 0

IN

I

= 12mA (24mA)

OL

I

= -6mA (-12mA)

OH

V

= 0 to V

IN

(Note 1)

cc

36

PARAMETER SYMBOL MIN TYP MAX UNITS COMMENTS

O12 Type Buffer

Low Output Level
High Output Level
Output Leakage

O12PD Type Buffer

Low Output Level
High Output Level
Output Leakage

O

Type Buffer

CLK

Low Output Level
High Output Level
Output Leakage

OD12 Type Buffer

Low Output Level
Output Leakage

Supply Current Activ e

Supply Current Standby

V
V

I

V
V

I

V
V

I

V

I
ICC

I

CSBY

OL

OH

OL

OL

OH

OL

OL

OH

OL

OL

OL

2.4

-10

2.4

-10

2.2

-10

-10

0.4

+10

0.4

+10

0.4

+10

0.4

+10

8

2.5

TABLE 34 - DC ELECTRICAL CHARACTERISTICS

Note 1: All output leakages are measured with the current pins in high impedance as defined by the
PWRGD pin.
Note 2: Output leakage is measured with the low driving output off, either for a high level output or
a high impedance state defined by PWRGD.
Note 3: Defined by the device configuration with the PWRGD input low.

Note 4: Junction Temperature rise at 70°C ambient will be approximately 1.7°C. Junction Temperature

rise = Ambient Temp. +0

ja x Max. Power; where 0ja = 56.8 and Max. Power = 3.6V x 8mA

V
V

µA

V
V

µA

V
V

µA

V

µA

mA

µA

I

= 12mA

OL

I

= -6mA

OH

V

= 0 to Vcc (Note 1)

IN

I

= 12mA (24mA)

OL

I

= -6mA (-12mA)

OH

V

= 0 to Vcc (Note 1)

IN

I

= 2mA

OL

I

= -2mA

OH

V

= 0 to Vcc (Note 1)

IN

I

= 12 mA

OL

V

= 0 to Vcc (Note 1)

IN

All outputs open.
Note 3

37

A.C. TIMING

X1/CLK1

Clock and Reset Timing

RESET DRV

TABLE 35 - CRYSTAL AND RESET TIMING PARAMETERS

NAME DESCRIPTION MIN TYP MAX UNITS

tcyc Clock Cycle Time 37 41 45 ns

txl Clock Low Pulse Width 18.5 20.5 22.5 ns

trst Reset Pulse Width 10 us

tcyc

txltxl

FIGURE 8 - EXTERNAL CLOCK INPUT TIMING

trsttrst

FIGURE 9 - RESET_DRV PULSE TIMING

38

Read Cycle Timing (Non-Multiplexed)

SA[4:0]

nCS

t5

t1

nRD

SD[7:0]

FIGURE 10 - READ CYCLE (NON-MULTIPLEXED ADDRESS AND DATA)

t3t3

t2 t4

TABLE 36 - READ CYCLE TIMING PARAMETERS (NON-MULTIPLEXED ADDRESS AND DATA)

NAME DESCRIPTION MIN TYP MAX UNITS

t1 Chip Select and Address Valid to Read

15 ns

Pulse Active
t2 Read Pulse Active to Data Valid 0 55 ns
t3 Read Pulse Width 85 ns
t4 Data Hold Time 5 ns
t5

Note 1

Read Pulse Active to Chip Select and

Address Invalid

15 ns

Note 1: Chip select must be latched internally and released when read pulse goes inactive.

39

Read Cycle Timing (Multiplexed)

nCS

ASTRB

nRD

t4 t9

t1

t8t8

t5

t10

t3t3

AD[7:0]

Address Data

t7 t2 t6

FIGURE 11 - READ CYCLE (MULTIPLEXED ADDRESS AND DATA)

TABLE 37 - READ CYCLE TIMING PARAMETERS (MULTIPLEXED ADDRESS AND DATA)

NAME DESCRIPTION MIN TYP MAX UNITS

t1 Address Strobe Setup Time 30 ns
t2 Read Pulse Active to Data Valid 55 ns
t3 Read Pulse Width 85 ns
t4 Address Strobe Inactive to Chip Select Active 0 8 ns
t5 Chip Select Active to Read Pulse Active 15 ns
t6 Data Hold Time 5 ns
t7 Address Strobe Hold Time 5 15 ns
t8 Address Strobe Pulse Width 23 ns
t9

Read Pulse Active to Chip Select Inactive 15 ns

Note 1

t10 Address Strobe Inactive to Read Pulse

15

Active

Note 1: Chip select must be latched internally and released when read pulse goes inactive.

40

Write Cycle Timing (Non-Multiplexed)

SA[4:0]

t5

nCS

t3t3

t1 t4

nWR

t2

SD[7:0]

FIGURE 12 - WRITE CYCLE (NON-MULTIPLEXED ADDRESS AND DATA)

TABLE 38 - WRITE CYCLE TIMING PARAMETERS (NON-MULTIPLEXED ADDRESS AND DATA)

NAME DESCRIPTION MIN TYP MAX UNITS

t1 Chip Select and Address Valid to Write Pulse

23 ns

Active
t2 Data Hold Time 8 ns
t3 Write Pulse Width 85 ns
t4 Data valid to Write Pulse Inactive 30 ns
t5

Note 1

Write Pulse Active to Chip Select and Address

Invalid

15 ns

Note 1: Chip select must be latched internally and released when write pulse goes inactive.

41

Write Cycle Timing (Multiplexed)

nCS

ASTRB

t7 t9

t1

t8

t3t3

nWR

AD[8:0]

t5

t10 t4

t2 t6

Address Data

FIGURE 13 - WRITE CYCLE (MULTIPLEXED ADDRESS AND DATA)

TABLE 39 - WRITE CYCLE TIMING PARAMETERS (MULTIPLEXED ADDRESS AND DATA)

NAME DESCRIPTION MIN TYP MAX UNITS

t1 Address Strobe Setup Time 30 ns
t2 Address Strobe Hold Time 8 15 ns
t3 Write Pulse Width 85 ns
t4 Data Valid to Write Pulse Inactive 30 ns
t5 Chip Select Active to Write Pulse Active 15 ns
t6 Data Hold Time 5 ns
t7 Address Strobe Inactive to nCS Active 0 5 ns
t8 Address Strobe Pulse Width 23 ns
t9

Write Pulse Active to Address Strobe Inactive 15 ns

Note 1

t10 Address Strobe Inactive to Write Pulse Active 10

Note 1: Chip select must be latched internally and released when write pulse goes inactive.

42

A

A

AD[

]

Read/Write Cycle Timing (Multiplexed)

nCS

t1

t8

STRB

R/nW

t7 t9

t5

t3t3

t10 t4

DSTRB

t2 t6

8:0

FIGURE 14 - READ/WRITE CYCLE (MULTIPLEXED ADDRESS AND DATA)

TABLE 40 - READ/WRITE CYCLE TIMING PARAMETERS (MULTIPLEXED ADDRESS AND DATA)

NAME DESCRIPTION MIN TYP MAX UNITS

t1 Address Strobe Setup Time 30 ns
t2 Address Strobe Hold Time 8 15 ns
t3 Data Strobe Pulse Width 85 ns
t4 Data Valid to R/nW Pulse Inactive 30 ns
t5 Chip Select Active to R/nW Pulse Active 15 ns
t6 Data Hold time 5 ns
t7 Address Strobe Inactive to nCS Active 0 5 ns
t8 Address Strobe Pulse Width 23 ns
t9

Note 1

t10 Address Strobe Inactive to R/nW Pulse Active 10

Note 1: Chip select must be latched internally and released when write pulse goes inactive.

R/nW Pulse Active to Address Strobe Inactive 15 ns

ddress Data

43

Single Transfer Mode DMA Timing

AEN

DRQ

t15

t3

t2
t16

nDACK

nRD or nWR

AD[7:0]

TC

t1

t19

t6
t5

t14 t8

t11

t17t17

t7 t9

t13t13

t12

FIGURE 15 - SINGLE TRANSFER MODE DMA TIMING

Refer to table on the following page.

t4t4

t18t18

t10

44

TABLE 41 - SINGLE TRANSFER MODE DMA TIMING PARAMETERS

NAME DESCRIPTION MIN TYP MAX UNITS

t1 nDACK Delay Time from DRQ High 0 ns
t2 DRQ Reset Delay from nRD or nWR 15 ns
t3 DRQ Reset Delay from nDACK Low 15 ns
t4 nDACK Inactive 30 ns
t5 nRD Delay from DRQ High 15 ns
t6 nWR Delay from DRQ High 15 ns
t7 Data Access Time from nRD Low 55 ns
t8 Data Set Up Time to nWR High 30 ns

t9 Data to Float Delay from nRD High 5 ns
t10 Data Hold Time from nWR High 5 ns
t11 nDACK Set Up to nWR/nRD Low 5 ns
t12 nDACK Hold after nWR/nRD High 5 ns
t13 TC Pulse Width 30 ns
t14 AEN Set Up to nRD/nWR 30 ns
t15 AEN Hold from nDACK 0 ns
t16 TC Active to DRQ Inactive 15 ns
t17 nRD/nWR Pulse Width 85 ns
t18 nRD/nWR Inactive 30 ns
t19 AEN Active to nDACK Active 0 ns

45

Burst Transfer Mode DMA Timing

AEN

DRQ

t1

nDACK

nRD or nWR

t19 t12

t11

t6

t5

t14

t17

t15

t3

t18

t2

t16

t4

t8

AD[7:0]

TC

t7 t9

t13

FIGURE 16 - BURST TRANSFER MODE DMA TIMING

Refer to table on the following page.

t10

46

TABLE 42 - DMA TIMING (BURST TRANSFER MODE) PARAMETERS

NAME DESCRIPTION MIN TYP MAX UNITS

t1 nDACK Delay Time from DRQ High 0 ns
t2 DRQ Reset Delay from nRD or nWR 15 ns
t3 DRQ Reset Delay from nDACK Low 15 ns
t4 nDACK Inactive 30 ns
t5 nRD Delay from DRQ High 15 ns
t6 nWR Delay from DRQ High 15 ns
t7 Data Access Time from nRD Low 55 ns
t8 Data Set Up Time to nWR High 30 ns
t9 Data to Float Delay from nRD High 5 ns

t10 Data Hold Time from nWR High 5 ns
t11 nDACK Set Up to nWR/nRD Low 5 ns
t12 nDACK Hold after nWR/nRD High 5 ns
t13 TC Pulse Width 30 ns
t14 AEN Set Up to nRD/nWR 15 ns
t15 AEN Hold from nDACK 0 ns
t16 TC Active to DRQ Inactive 15 ns
t17 nRD/nWR Pulse Width 85 ns
t18 nRD/nWR Inactive 30 ns
t19 AEN Active to nDACK Active 0 ns

47

FIGURE 17 - 48 PIN TQFP PACKAGE OUTLINE

MIN NOMINAL MAX REMARK

A ~ ~ 1.6 Overall Package Height
A1 0.05 0.10 0.15 Standoff
A2 1.35 1.40 1.45 Body Thickness

D ~ 9.00 ~ X Span

D/2 4.40 4.50 4.60 1/2 X Span Measure from Centerline
D1 ~ 7.00 ~ X body Size

E ~ 9.00 ~ Y Span

E/2 4.40 4.50 4.60 1/2 Y Span Measure from Centerline

E1 ~ 7.00 ~ Y body Size

H 0.09 ~ 0.20 Lead Frame Thickness

L 0.45 0.60 0.75 Lead Foot Length from Centerline

L1 ~ 1.00 ~ Lead Length

e 0.50 Basic Lead Pitch

%"

o

~ 7o Lead Foot Angle

0

W 0.17 ~ 0.27 Lead Width

R1 0.08 ~ ~ Lead Shoulder Radius

48

MIN NOMINAL MAX REMARK

R2 0.08 ~ 0.20 Lead Foot Radius

ccc ~ ~ 0.0762 Coplanarity (Assemblers)
ccc ~ ~ 0.08 Coplanarity (Test House)

Note 1: Controlling Unit: millimeter
Note 2: Tolerance on the position of the leads is ± 0.04 mm maximum.
Note 3: Package body dimensions D1 and E1 do not include the mold protrusion. Maximum mold

protrusion is 0.25 mm.

Note 4: Dimension for foot length L measured at the gauge plane 0.25 mm above the seating plane is

0.78-1.08 mm.

Note 5: Details of pin 1 identifier are optional but must be located within the zone indicated.

CAM35C44 ERRATA SHEET

PAGE

1 GENERAL DESCRIPTION 24mA changed to 12mA 1/7/98

10 DESCRIPTION OF PIN
21 TABLE 13/REGISTER NAME See Italicized Text 1/7/98

29 TABLE 25 See Italicized Text 1/7/98
37 Note 4 added See Italicized Text 1/7/98
29 TABLE 25
37 TABLE 34 – MAX Column See Italicized Text 8/10/99

SECTION/FIGURE/ENTRY

FUNCTIONS

CORRECTION

See Italicized Text 1/7/98

2#A changed to 2.5#A

DATE

REVISED

8/10/99

49

© 2000 STANDARD MICROSYSTEMS CORPORATION (SMSC)

80 Arkay Drive
Hauppauge, NY 11788
[phone]
FAX [phone]

Standard Microsystems is a registered trademark of Standard Microsystems Corporation, and SMSC is a trademark of Standard
Microsystems Corporation. Product names and company names are the trademarks of their respective holders. Circuit diagrams
utilizing SMSC products are included as a means of illustrating typical applications; consequently complete information sufficient for
construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no
responsibility is assumed for inaccuracies. SMSC reserves the right to make changes to specifications and product descriptions at any
time without notice. Contact your local SMSC sales office to obtain the latest specifications before placing your product order. The
provision of this inform ation does not convey to the purchaser of the sem iconductor devices described any licenses under the patent
rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated
version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The
product may contain design defects or errors k nown as anomalies which may cause the product's functions to deviate from published
specifications. Anomaly sheets are available upon request. S MSC products are not designed, intended, authorized or warranted for
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CAM35C44 Rev. 03/22/2000