ATMEL AT83C5136 User Manual

BDTIC www.BDTIC.com/ATMEL

Features

• 80C52X2 Core (6 Clocks per Instruction)

– Maximum Core Frequency 48 MHz in X1 Mode, 24 MHz in X2 Mode – Dual Data Pointer – Full-duplex Enhanced UART (EUART), TxD and Rxd are 5 Volt Tolerant – Three 16-bit Timer/Counters: T0, T1 and T2 – 256 Bytes of Scratchpad RAM

• 8/16/32-Kbyte On-chip ROM

• 512 byte or 32-Kbyte EEPROM

• On-chip Expanded RAM (ERAM): 1024 Bytes

• Integrated Power Monitor (POR/PFD) to Supervise Internal Power Supply

• USB 2.0 Full Speed Compliant Module with Interrupt on Transfer Completion (12Mbps)

– Endpoint 0 for Control Transfers: 32-byte FIFO – 6 Programmable Endpoints with In or Out Directions and with Bulk, Interrupt or

Isochronous Transfers

• Endpoint 1, 2, 3: 32-byte FIFO

• Endpoint 4, 5: 2 x 64-byte FIFO with Double Buffering (Ping-pong Mode) – Suspend/Resume Interrupts – Power-on Reset and USB Bus Reset – 48 MHz DPLL for Full-speed Bus Operation – USB Bus Disconnection on Microcontroller Request

• 5 Channels Programmable Counter Array (PCA) with 16-bit Counter, High-speed

Output, Compare/Capture, PWM and Watchdog Timer Capabilities

• Programmable Hardware Watchdog Timer (One-time Enabled with Reset-out): 50 ms to

6s at 4 MHz

• Keyboard Interrupt Interface on Port P1 (8 Bits)

• TWI (Two Wire Interface) 400Kbit/s

• SPI Interface (Master/Slave Mode) MISO,MOSI,SCK and SS are 5 Volt Tolerant

• 34 I/O Pins

• 4 Direct-drive LED Outputs with Programmable Current Sources: 2-6-10 mA Typical

• 4-level Priority Interrupt System (11 sources)

• Idle and Power-down Modes

• 0 to 32 MHz On-chip Oscillator with Analog PLL for 48 MHz Synthesis

• Industrial Temperature Range

• Low Voltage Range Supply: 2.7V to 3.6V

• Packages: Die SO28, QFN32, MLF48, TQFP64

(1)

8-bit Microcontroller with Full Speed USB Device

AT83C5134 AT83C5135 AT83C5136

Notes: 1. EEPROM only available on MLF48

1. Description

AT83C5134/35/36 are high performance ROM versions of the 80C51 single-chip 8-bit microcontrollers with full speed USB functions.

AT83C5134/35 is pin compatible with AT89C5130A 16Kbytes In-System Programmable Flash microcontrollers.

AT83C5134/35/36

This allows to use AT89C5130A for development, pre-production and flexibility, while using AT83C5134/35 for cost reduction in mass production. Similarly AT83C5136 is pin compatible with AT89C5131A 32-Kbytes Flash microcontroller.

AT83C5134/35/36 features a full-speed USB module compatible with the USB specifications Version 2.0. This module integrates the USB transceivers and the Serial Interface Engine (SIE) with Digital Phase Locked Loop and 48 MHz clock recovery. USB Event detection logic (Reset and Suspend/Resume) and FIFO buffers supporting the mandatory control Endpoint (EP0) and 5 versatile Endpoints (EP1/EP2/EP3/EP4/EP5) with minimum software overhead are also part of the USB module.

AT83C5134/35/36 retains the features of the Atmel 80C52 with extended ROM cpacity (8/16/32 Kbytes), 256 bytes of internal RAM, a 4-level interrupt system, two 16-bit timer/counters (T0/T1), a full duplex enhanced UART (EUART) and an on-chip oscillator.

In addition, AT83C5134/35/36 has an on-chip expanded RAM of 1024 bytes (ERAM), a dualdata pointer, a 16-bit up/down Timer (T2), a Programmable Counter Array (PCA), up to 4 programmable LED current sources, a programmable hardware watchdog and a power-on reset.

AT83C5134/35/36 has two software-selectable modes of reduced activity for further reduction in power consumption. In the idle mode the CPU is frozen while the timers, the serial ports and the interrupt system are still operating. In the power-down mode the RAM is saved, the peripheral clock is frozen, but the device has full wake-up capability through USB events or external interrupts.

7683C–USB–11/07

3. Block Diagram

Timer 0

INT

RAM

256x8

RxD

TxD

PSEN

ALE

XTAL2

XTAL1

EUART

CPU

Timer 1

INT1

Ctrl

INT0

(2)

C51

CORE

(2) (2) (2) (2)

Port 0P0Port 1

Port 2

Port 3

Parallel I/O Ports & Ext. Bus

ERAM

1Kx8

PCA

RST

Watch

Dog

CEX

ECI

VSS

VDD

(2)(2)

(1)(1)

Timer2

T2EX

(1) (1)

Port 4

32Kx8 ROM

BRG

USB

D -

D +

Key

Board

KIN

EEPROM*

1Kx8

SPI

MISO

MOSI

SCK

(1) (1) (1)

(1)

TWI

SCL

SDA

TWI interface

AT83C5134/35/36

Notes: 1. Alternate function of Port 1

2. Alternate function of Port 3

3. Alternate function of Port 4

* EEPROM only available in MLF48

7683C–USB–11/07

AT83C5134/35/36

4. Pinout Description

P3.4/T0

P3.5/T1/LED1

ALE

PSEN

PLLF

VREF

D-

D+

17 18 22212019 252423 26 27

62 61 60 59 58 63

57 56 55 54 53

1 2

48 47

41 40

VQFP64

12 13

51 50

15 16

31 32

P1.1/T2EX/KIN1/SS

P1.7/CEX4/KIN7/MOSI

P1.3/CEX0/KIN3

P1.5/CEX2/KIN5/MISO

P1.6/CEX3/KIN6/SCK

P2.7/A15

P2.6/A14

P4.1/SDA

P1.2/ECI/KIN2

P1.4/CEX1/KIN4

P1.0/T2/KIN0

XTAL2

RST

P3.7/RD/LED3

P2.0/A8

P2.1/A9

P2.2/A10

P2.3/A11

P2.4/A12

P3.0/RxD

P0.0/AD0

AVSS

P3.2/INT0

P3.6/WR/LED2

P3.1/TxD

P3.3/INT1/LED0

VSS

P0.6/AD6 P0.7/AD7

P2.5/A13

P0.3/AD3

P0.5/AD5

P0.4/AD4

P0.2/AD2

P0.1/AD1

P4.0/SCL

XTAL1

AVDD

VDD

4.1 Pinout

Figure 4-1. AT83C5134/35/36 64-pin VQFP Pinout

7683C–USB–11/07

Figure 4-2. AT83C5134/35/36 48-pin MLF Pinout

46 45 44 43 42 41 40 39 38

MLF48

P1.1/T2EX/KIN1/SS

P1.0/T2/KIN0

P0.6/AD6

ALE

P0.7/AD7

PSEN

P1.7/CEX4/KIN7/MOSI

P1.3/CEX0/KIN3

P1.5/CEX2/KIN5/MISO

P1.6/CEX3/KIN6/SCK

PLLF

P3.0/RxD

AVSS

P2.6/A14

XTAL1

P2.5/A13

P0.3/AD3

P0.5/AD5

P0.4/AD4

VREF

P0.2/AD2

P0.0/AD0

P0.1/AD1

AVDD

P3.2/INT0

P3.6/WR/LED2

XTAL2

RST

P3.1/TxD

P3.3/INT1/LED0

P3.7/RD/LED3

D-

P2.1/A9

P2.2/A10

P2.3/A11

VSS

P2.4/A12

P4.1/SDA

D+

P4.0/SCL

P1.2/ECI/KIN2

P1.4/CEX1/KIN4

P3.4/T0

P3.5/T1/LED1

VDD

P2.7/A15

29 28

23 22 21

P2.0/A8

P1.1/T2EX/KIN1/SS

PLLF

P3.0/RxD

P1.0/T2/KIN0

AVSS

VDD

XTAL1

XTAL2

P3.2/INT0

P3.5/T1/LED1

P3.6/WR/LED2

P3.7/RD/LED3

D-

P1.4/CEX1/KIN4

VSS

D+

P1.2/ECI/KIN2

P1.3/CEX0/KIN3

P1.5/CEX2/KIN5/MISO

RST

P1.6/CEX3/KIN6/SCK

P1.7/CEX4/KIN7/MOSI

P4.0/SCL

VREF P3.1/TxD

P3.4/T0

3 4

7 8

27 26

24 23

19 18

SO28

P4.1/SDA

P3.3/INT1/LED0

AT83C5134/35/36

7683C–USB–11/07

Figure 4-3. AT83C5134/35/36 28-pin SO Pinout

AT83C5134/35/36

Figure 4-4. AT83C5134/35/36 32-pin QFN Pinout

QFN32

P1.1/T2EX/KIN1/SS

P1.7/CEX4/KIN7/MOSI

P1.3/CEX0/KIN3

P1.5/CEX2/KIN5/MISO

P1.6/CEX3/KIN6/SCK

P3.0/RxD

AVSS

XTAL1

VREF

AVDD

P3.2/INT0

P3.5/T1/LED1

XTAL2

RST

P3.1/TxD

P3.3/INT1/LED0

P3.7/RD/LED3

D-

VSS

P4.1/SDA

D+

P4.0/SCL

P1.2/ECI/KIN2

P1.4/CEX1/KIN4

P3.4/T0

P1.0/T2/KIN0

VDD

PLLF

P3.6/WR/LED2

UVSS

VSS

9 10 11 12 13 14 15 16

32 31 30 29 28 27 26 25

Note : The metal plate can be connected to Vss

4.2 Signals

All the AT83C5134/35/36 signals are detailed by functionality on Table 4-1 through Table 4-12.

Table 4-1. Keypad Interface Signal Description

Signal

Name Type Description

KIN[7:0) I

Table 4-2. Programmable Counter Array Signal Description

Signal

CEX[4:0] I/O

Name Type Description

ECI I External Clock Input P1.2

Keypad Input Lines

Holding one of these pins high or low for 24 oscillator periods triggers a keypad interrupt if enabled. Held line is reported in the KBCON register.

Capture External Input

Compare External Output

Alternate Function

P1[7:0]

Alternate Function

P1.3

P1.4

P1.5

P1.6

P1.7

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Table 4-3. Serial I/O Signal Description

AT83C5134/35/36

Signal

Name Type Description

RxD I

TxD O

Serial Input

The serial input for Extended UART. This I/O is 5 Volt Tolerant.

Serial Output

The serial output for Extended UART. This I/O is 5 Volt Tolerant.

Table 4-4. Timer 0, Timer 1 and Timer 2 Signal Description

Signal

Name Type Description

Timer 0 Gate Input

INT0 serves as external run control for timer 0, when selected by GATE0 bit in TCON register.

INT0 I

INT1 I

External Interrupt 0

INT0 input set IE0 in the TCON register. If bit IT0 in this register is set, bits IE0 are set by a falling edge on INT0. If bit IT0 is cleared, bits IE0 is set by a low level on INT0.

Timer 1 Gate Input

INT1 serves as external run control for Timer 1, when selected by GATE1 bit in TCON register.

External Interrupt 1

INT1 input set IE1 in the TCON register. If bit IT1 in this register is set, bits IE1 are set by a falling edge on INT1. If bit IT1 is cleared, bits IE1 is set by a low level on INT1.

Alternate Function

P3.0

P3.1

Alternate Function

P3.2

P3.3

T0 I

T1 I

T2EX I Timer/Counter 2 Reload/Capture/Direction Control Input P1.1

Timer Counter 0 External Clock Input

When Timer 0 operates as a counter, a falling edge on the T0 pin increments the count.

Timer/Counter 1 External Clock Input

When Timer 1 operates as a counter, a falling edge on the T1 pin increments the count.

IOTimer/Counter 2 External Clock Input

Timer/Counter 2 Clock Output

Table 4-5. LED Signal Description

Signal

Name Type Description

Direct Drive LED Output

These pins can be directly connected to the Cathode of standard LEDs without

LED[3:0] O

external current limiting resistors. The typical current of each output can be programmed by software to 2, 6 or 10 mA. Several outputs can be connected together to get higher drive capabilities.

P3.4

P3.5

P1.0

Alternate Function

P3.3

P3.5

P3.6

P3.7

7683C–USB–11/07

AT83C5134/35/36

Table 4-6. TWI Signal Description

Signal

Name Type Description

SCL I/O

SDA I/O

SCL: TWI Serial Clock

SCL output the serial clock to slave peripherals. SCL input the serial clock from master.

SDA: TWI Serial Data

SCL is the bidirectional TWI data line.

Table 4-7. SPI Signal Description

Signal

Name Type Description

SS I/O SS: SPI Slave Select . This I/O is 5 Volt tolerant P1.1

MISO: SPI Master Input Slave Output line

MISO I/O

SCK I/O

MOSI

When SPI is in master mode, MISO receives data from the slave peripheral. When SPI is in slave mode, MISO outputs data to the master controller. This I/O is 5 Volt tolerant

SCK: SPI Serial Clock

SCK outputs clock to the slave peripheral or receive clock from the master.

This I/O is 5 Volt tolerant.

MOSI: SPI Master Output Slave Input line

I/O

When SPI is in master mode, MOSI outputs data to the slave peripheral. When SPI is in slave mode, MOSI receives data from the master controller.

This I/O is 5 Volt tolerant.

Alternate Function

P4.0

P4.1

Alternate Function

P1.5

P1.6

P1.7

Table 4-8. Ports Signal Description

Signal

Name Type Description Alternate Function

Port 0

P0 is an 8-bit open-drain bidirectional I/O port. Port 0 pins that

P0[7:0] I/O

P1[7:0] I/O

P2[7:0] I/O

have 1s written to them float and can be used as high impedance inputs. To avoid any parasitic current consumption, Floating P0 inputs must be pulled to V

Port 1

P1 is an 8-bit bidirectional I/O port with internal pull-ups.

Port 2

P2 is an 8-bit bidirectional I/O port with internal pull-ups.

or VSS.

AD[7:0]

KIN[7:0]

T2EX

ECI

CEX[4:0]

A[15:8]

7683C–USB–11/07

AT83C5134/35/36

Signal

Name Type Description Alternate Function

LED[3:0]

RxD

TxD

P3[7:0] I/O

Port 3

P3 is an 8-bit bidirectional I/O port with internal pull-ups.

INT0 INT1

T0 T1

P4[1:0] I/O

Port 4

P4 is an 2-bit open port.

Table 4-9. Clock Signal Description

Signal

Name Type Description

XTAL1 I

XTAL2 O

PLLF I

Input to the on-chip inverting oscillator amplifier

To use the internal oscillator, a crystal/resonator circuit is connected to this pin. If an external oscillator is used, its output is connected to this pin.

Output of the on-chip inverting oscillator amplifier

To use the internal oscillator, a crystal/resonator circuit is connected to this pin. If an external oscillator is used, leave XTAL2 unconnected.

PLL Low Pass Filter input

Receives the RC network of the PLL low pass filter (See Figure 5-1 on page 11 ).

Table 4-10. USB Signal Description

Signal

Name Type Description

D+ I/O

USB Data + signal

Set to high level under reset.

SCL

SDA

Alternate Function

7683C–USB–11/07

D- I/O

VREF O

USB Data - signal

Set to low level under reset.

USB Reference Voltage

Connect this pin to D+ using a 1.5 kΩ resistor to use the Detach function.

Table 4-11. System Signal Description

Signal

Name Type Description

AD[7:0] I/O

A[15:8] I/O

Multiplexed Address/Data LSB for external access

Data LSB for Slave port access (used for 8-bit and 16-bit modes)

Address Bus MSB for external access

Data MSB for Slave port access (used for 16-bit mode only)

Alternate Function

P0[7:0]

P2[7:0]

AT83C5134/35/36

Signal

Name Type Description

Read Signal

RD I/O

WR I/O

RST I/O

ALE O

Read signal asserted during external data memory read operation.

Control input for slave port read access cycles.

Write Signal

Write signal asserted during external data memory write operation.

Control input for slave write access cycles.

Reset

Holding this pin low for 64 oscillator periods while the oscillator is running resets the device. The Port pins are driven to their reset conditions when a voltage lower than VIL is applied, whether or not the oscillator is running. This pin has an internal pull-up resistor which allows the device to be reset by connecting a capacitor between this pin and VSS. Asserting RST when the chip is in Idle mode or Power-down mode returns the chip to normal operation. This pin is set to 0 for at least 12 oscillator periods when an internal reset occurs (hardware watchdog or Power monitor).

Address Latch Enable Output

The falling edge of ALE strobes the address into external latch. This signal is active only when reading or writing external memory using MOVX instructions.

Alternate Function

P3.7

P3.6

PSEN O

EA I

Program Strobe Enable / Hardware conditions Input for ISP

Used as input under reset to detect external hardware conditions of ISP mode

External Access Enable

This pin must be held low to force the device to fetch code from external program memory starting at address 0000h. It is latched during reset and cannot be dynamically changed during operation.

Table 4-12. Power Signal Description

Signal

Name Type Description

AVSS GND

AVDD PWR

VSS GND

VDD PWR

VREF O

Alternate Ground

AVSS is used to supply the on-chip PLL and the USB PAD.

Alternate Supply Voltage

AVDD is used to supply the on-chip PLL and the USB PAD.

Digital Ground

VSS is used to supply the buffer ring and the digital core.

Digital Supply Voltage

VDD is used to supply the buffer ring on all versions of the device.

It is also used to power the on-chip voltage regulator of the Standard versions or the digital core of the Low Power versions.

USB pull-up Controlled Output

VREF is used to control the USB D+ 1.5 kΩ pull up.

The Vref output is in high impedance when the bit DETACH is set in the USBCON register.

Alternate Function

7683C–USB–11/07

5. Typical Application

VSS

XTAL1

XTAL2

22pF

VSS

PLLF

560

820pF

150pF

VSS

AVSS

VSS

D-

D+

27R

VRef

1.5K

USB

D+

D-

VBUS

GND

VSS

VDD

AVDD

VDD

4.7µF

VSS

100nF

VSS

100nF

VSS

AT83C5134/35/3

5.1 Recommended External components

All the external components described in the figure below must be implemented as close as possible from the microcontroller package.

The following figure represents the typical wiring schematic.

Figure 5-1. Typical Application

AT83C5134/35/36

7683C–USB–11/07

AT83C5134/35/36

5.2 PCB Recommandations

D+

VRef

D-

USB Connector

Wires must be routed in Parallel and

Components must be

If possible, isolate D+ and D- signals from other signals with ground wires

must be as short as possible

close to the microcontroller

PLLFAVss

Components must be

Isolate filter components

with a ground wire

microcontroller

close to the

Figure 5-2. USB Pads

Note: No sharp angle in above drawing.

Figure 5-3. USB PLL

7683C–USB–11/07

6. Clock Controller

PCON.1

IDL

PCON.0

Peripheral

CPU Core

CKCON.0

Clock

EXT48

PLLCON.2

PLL

USB Clock

6.1 Introduction

The AT83C5134/35/36 clock controller is based on an on-chip oscillator feeding an on-chip Phase Lock Loop (PLL). All the internal clocks to the peripherals and CPU core are generated by this controller.

The AT83C5134/35/36 X1 and X2 pins are the input and the output of a single-stage on-chip inverter (see Figure 6-1) that can be configured with off-chip components as a Pierce oscillator (see Figure 6-2). Value of capacitors and crystal characteristics are detailed in the section “DC Characteristics”.

The X1 pin can also be used as input for an external 48 MHz clock.

The clock controller outputs three different clocks as shown in Figure 6-1:

• a clock for the CPU core

• a clock for the peripherals which is used to generate the Timers, PCA, WD, and Port

• a clock for the USB controller

These clocks are enabled or disabled depending on the power reduction mode as detailed in Section “Power Management”, page 135.

AT83C5134/35/36

sampling clocks

Figure 6-1. Oscillator Block Diagram

6.2 Oscillator

Two clock sources are available for CPU:

• Crystal oscillator on X1 and X2 pins: Up to 32 MHz

• External 48 MHz clock on X1 pin

7683C–USB–11/07

AT83C5134/35/36

6.3 PLL

VSS

PLLEN

PLLCON.1

N3:0

N divider

R divider

VCO USB Clock

US Bclk

OSCclk R 1+( )×

N 1+

-----------------------------------------------=

PFLD

PLOCK

PLLCON.0

PLLF

CHP

Vref

Down

R3:0

USB

CLOCK

USB Clock Symbol

6.3.1 PLL Description

In order to optimize the power consumption, the oscillator inverter is inactive when the PLL output is not selected for the USB device.

Figure 6-2. Crystal Connection

The AT83C5134/35/36 PLL is used to generate internal high frequency clock (the USB Clock) synchronized with an external low-frequency (the Peripheral Clock). The PLL clock is used to generate the USB interface clock. Figure 6-3 shows the internal structure of the PLL.

The PFLD block is the Phase Frequency Comparator and Lock Detector. This block makes the comparison between the reference clock coming from the N divider and the reverse clock coming from the R divider and generates some pulses on the Up or Down signal depending on the edge position of the reverse clock. The PLLEN bit in PLLCON register is used to enable the clock generation. When the PLL is locked, the bit PLOCK in PLLCON register (see Figure 6-3) is set.

The CHP block is the Charge Pump that generates the voltage reference for the VCO by injecting or extracting charges from the external filter connected on PLLF pin (see Figure 6-4). Value of the filter components are detailed in the Section “DC Characteristics”.

The VCO block is the Voltage Controlled Oscillator controlled by the voltage V the charge pump. It generates a square wave signal: the PLL clock.

Figure 6-3. PLL Block Diagram and Symbol

produced by

REF

7683C–USB–11/07

Figure 6-4. PLL Filter Connection

VSS

PLLF

VSS

PLL

Programming

Configure Dividers

N3:0 = xxxxb R3:0 = xxxxb

Enable PLL

PLLEN = 1

PLL Locked?

LOCK = 1?

The typical values are: R = 560 Ω, C1 = 820 pf, C2 = 150 pF.

6.3.2 PLL Programming

The PLL is programmed using the flow shown in Figure 6-5. As soon as clock generation is enabled user must wait until the lock indicator is set to ensure the clock output is stable.

Figure 6-5. PLL Programming Flow

AT83C5134/35/36

6.3.3 Divider Values

7683C–USB–11/07

To generate a 48 MHz clock using the PLL, the divider values have to be configured following the oscillator frequency. The typical divider values are shown in Table 6-1.

Table 6-1. Typical Divider Values

Oscillator Frequency R+1 N+1 PLLDIV

3 MHz 16 1 F0h

6 MHz 8 1 70h

8 MHz 6 1 50h

12 MHz 4 1 30h

16 MHz 3 1 20h

18 MHz 8 3 72h

20 MHz 12 5 B4h

24 MHz 2 1 10h

AT83C5134/35/36

6.4 Registers

Oscillator Frequency R+1 N+1 PLLDIV

32 MHz 3 2 21h

40 MHz 12 10 B9h

Table 6-2. CKCON0 (S:8Fh)

Clock Control Register 0

7 6 5 4 3 2 1 0

TWIX2 WDX2 PCAX2 SIX2 T2X2 T1X2 T0X2 X2

Bit Number

7 TWIX2

6 WDX2

5 PCAX2

4 SIX2

3 T2X2

Bit

Mnemonic Description

TWI Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

Watchdog Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

Programmable Counter Array Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

Enhanced UART Clock (Mode 0 and 2) This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

Timer2 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

Timer1 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit

2 T1X2

1 T0X2

0 X2

has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

Timer0 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

System Clock Control bit

Clear to select 12 clock periods per machine cycle (STD mode, F Set to select 6 clock periods per machine cycle (X2 mode, F

Reset Value = 0000 0000b

= F

CPU

CPU = FPER = FOSC

PER = FOSC

7683C–USB–11/07

2).

AT83C5134/35/36

Table 6-3. CKCON1 (S:AFh)

Clock Control Register 1

7 6 5 4 3 2 1 0

- - - - - - - SPIX2

Bit Number

7-1 -

0 SPIX2

Bit

Mnemonic Description

Reserved

The value read from this bit is always 0. Do not set this bit.

SPI Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect.

Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle.

Reset Value = 0000 0000b

Table 6-4. PLLCON (S:A3h)

PLL Control Register

7 6 5 4 3 2 1 0

- - - - - EXT48 PLLEN PLOCK

Bit Number

7-3 -

2 EXT48

Bit

Mnemonic Description

Reserved

The value read from this bit is always 0. Do not set this bit.

External 48 MHz Enable Bit

Set this bit to bypass the PLL and disable the crystal oscillator. Clear this bit to select the PLL output as USB clock and to enable the crystal oscillator.

7683C–USB–11/07

PLL Enable Bit

1 PLLEN

0 PLOCK

Set to enable the PLL. Clear to disable the PLL.

PLL Lock Indicator

Set by hardware when PLL is locked. Clear by hardware when PLL is unlocked.

Reset Value = 0000 0000b

Table 6-5. PLLDIV (S:A4h)

PLL Divider Register

7 6 5 4 3 2 1 0

R3 R2 R1 R0 N3 N2 N1 N0

Bit Number

7-4 R3:0 PLL R Divider Bits

3-0 N3:0 PLL N Divider Bits

Bit

Mnemonic Description

Reset Value = 0000 0000

AT83C5134/35/36

7. SFR Mapping

The Special Function Registers (SFRs) of the AT83C5134/35/36 fall into the following categories:

• C51 core registers: ACC, B, DPH, DPL, PSW, SP

• I/O port registers: P0, P1, P2, P3, P4

• Timer registers: T2CON, T2MOD, TCON, TH0, TH1, TH2, TMOD, TL0, TL1, TL2, RCAP2L, RCAP2H

• Serial I/O port registers: SADDR, SADEN, SBUF, SCON

• PCA (Programmable Counter Array) registers: CCON, CMOD, CCAPMx, CL, CH, CCAPxH, CCAPxL (x: 0 to 4)

• Power and clock control registers: PCON

• Hardware Watchdog Timer registers: WDTRST, WDTPRG

• Interrupt system registers: IEN0, IPL0, IPH0, IEN1, IPL1, IPH1

• Keyboard Interface registers: KBE, KBF, KBLS

• LED register: LEDCON

• Two Wire Interface (TWI) registers: SSCON, SSCS, SSDAT, SSADR

• Serial Port Interface (SPI) registers: SPCON, SPSTA, SPDAT

• USB registers: Uxxx (17 registers)

• PLL registers: PLLCON, PLLDIV

• BRG (Baud Rate Generator) registers: BRL, BDRCON

• Others: AUXR, AUXR1, CKCON0, CKCON1

7683C–USB–11/07

The table below shows all SFRs with their address and their reset value.

Reserved

Table 7-1. SFR Descriptions

Bit

Addressable Non-Bit Addressable

0/8 1/9 2/A 3/B 4/C 5/D 6/E 7/F

AT83C5134/35/36

F8h

F0h

E8h

E0h

D8h

D0h

C8h

C0h

B8h

B0h

UEPINT

0000 0000

ACC

0000 0000

CCON

00X0 0000

PSW

0000 0000

T2CON

0000 0000

XXXX 1111

IPL0

X000 000

1111 1111

0000 0000

LEDCON

0000 0000

CMOD

00XX X000

T2MOD

XXXX XX00

SADEN

0000 0000

IEN1

X0XX X000

CCAP0H

XXXX XXXX

CCAP0L

XXXX XXXX

UBYCTLX

0000 0000

CCAPM0

X000 0000

RCAP2L

0000 0000

UEPIEN

0000 0000

UFNUML

0000 0000

IPL1

X0XX X000

CCAP1H

XXXX XXXX

CCAP1L

XXXX XXXX

UBYCTHX 0000 0000

CCAPM1

X000 0000

RCAP2H

0000 0000

SPCON

0001 0100

UFNUMH

0000 0000

IPH1

X0XX X000

CCAP2H

XXXX XXXX

CCAP2L

XXXX XXXX

CCAPM2

X000 0000

UEPCONX 1000 0000

TL2

0000 0000

SPSTA

0000 0000

USBCON

0000 0000

CCAP3H

XXXX XXXX

CCAP3L

XXXX XXXX

CCAPM3

X000 0000

UEPRST

0000 0000

TH2

0000 0000

SPDAT

XXXX XXXX

USBINT

0000 0000

CCAP4H

XXXX XXXX

CCAP4L

XXXX XXXX

CCAPM4

X000 0000

UEPSTAX

0000 0000

USBADDR 1000 0000

USBIEN

0000 0000

UEPDATX 0000 0000

UEPNUM

0000 0000

IPH0

X000 0000

FFh

F7h

EFh

E7h

DFh

D7h

CFh

C7h

BFh

B7h

A8h

A0h

98h

90h

88h

80h

IEN0

0000 0000

1111 1111

SCON

0000 0000

1111 1111

TCON

0000 0000

1111 1111

0/8 1/9 2/A 3/B 4/C 5/D 6/E 7/F

SADDR

0000 0000

SBUF

XXXX XXXX

TMOD

0000 0000

0000 0111

AUXR1

XXXX X0X0

BRL

0000 0000

TL0

0000 0000

DPL

0000 0000

PLLCON

XXXX XX00

BDRCON

XXX0 0000

SSCON

0000 0000

TL1

0000 0000

DPH

0000 0000

PLLDIV

0000 0000

1111 1000

0000 0000

Note: 1. FCON access is reserved for the Flash API and ISP software.

The Special Function Registers (SFRs) of the AT89C5131 fall into the following categories:

KBLS

SSCS

TH0

KBE

0000 0000

SSDAT

1111 1111

TH1

0000 0000

WDTRST

XXXX XXXX

KBF

0000 0000

SSADR

1111 1110

AUXR

XX0X 0000

CKCON1

0000 0000

WDTPRG

XXXX X000

CKCON0

0000 0000

PCON

00X1 0000

AFh

A7h

9Fh

97h

8Fh

87h

7683C–USB–11/07

AT83C5134/35/36

Table 7-2. C51 Core SFRs

Mnemonic Add Name 7 6 5 4 3 2 1 0

ACC E0h Accumulator

B F0h B Register

PSW D0h

SP 81h

DPL 82h

DPH 83h

Program Status Word

Stack Pointer

LSB of SPX

Data Pointer Low byte

LSB of DPTR

Data Pointer High byte

MSB of DPTR

Table 7-3. I/O Port SFRs

Mnemonic Add Name 7 6 5 4 3 2 1 0

P0 80h Port 0

P1 90h Port 1

P2 A0h Port 2

P3 B0h Port 3

P4 C0h Port 4 (2bits)

Table 7-4. Timer SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

TH0 8Ch Timer/Counter 0 High byte

TL0 8Ah Timer/Counter 0 Low byte

TH1 8Dh Timer/Counter 1 High byte

TL1 8Bh Timer/Counter 1 Low byte

TH2 CDh Timer/Counter 2 High byte

TL2 CCh Timer/Counter 2 Low byte

TCON 88h

TMOD 89h

T2CON C8h Timer/Counter 2 control TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2# CP/RL2#

T2MOD C9h Timer/Counter 2 Mode T2OE DCEN

Timer/Counter 0 and 1 control

Timer/Counter 0 and 1 Modes

TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0

GATE1 C/T1# M11 M01 GATE0 C/T0# M10 M00

7683C–USB–11/07

AT83C5134/35/36

Table 7-4. Timer SFR’s (Continued)

Mnemonic Add Name 7 6 5 4 3 2 1 0

RCAP2H CBh

RCAP2L CAh

WDTRST A6h WatchDog Timer Reset

WDTPRG A7h WatchDog Timer Program S2 S1 S0

Timer/Counter 2 Reload/Capture High byte

Timer/Counter 2 Reload/Capture Low byte

Table 7-5. Serial I/O Port SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

SCON 98h Serial Control FE/SM0 SM1 SM2 REN TB8 RB8 TI RI

SBUF 99h Serial Data Buffer

SADEN B9h Slave Address Mask

SADDR A9h Slave Address

Table 7-6. Baud Rate Generator SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

BRL 9Ah Baud Rate Reload

BDRCON 9Bh Baud Rate Control BRR TBCK RBCK SPD SRC

Table 7-7. PCA SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

CCON D8h PCA Timer/Counter Control CF CR CCF4 CCF3 CCF2 CCF1 CCF0

CMOD D9h PCA Timer/Counter Mode CIDL WDTE CPS1 CPS0 ECF

CL E9h PCA Timer/Counter Low byte

CH F9h PCA Timer/Counter High byte

CCAPM 0

CCAPM 1

CCAPM 2

CCAPM 3

CCAPM 4

DAh

PCA Timer/Counter Mode 0

DBh

PCA Timer/Counter Mode 1

DCh

PCA Timer/Counter Mode 2

DDh

PCA Timer/Counter Mode 3

DEh

PCA Timer/Counter Mode 4

ECOM0

ECOM1

ECOM2

ECOM3

ECOM4

CAPP0

CAPP1

CAPP2

CAPP3

CAPP4

CAPN0

CAPN1

CAPN2

CAPN3

CAPN4

MAT0

MAT1

MAT2

MAT3

MAT4

TOG0

TOG1

TOG2

TOG3

TOG4

PWM0

PWM1

PWM2

PWM3

PWM4

ECCF0

ECCF1

ECCF2

ECCF3

ECCF4

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AT83C5134/35/36

Table 7-7. PCA SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

CCAP0 H

CCAP1 H

CCAP2 H

CCAP3 H

CCAP4 H

CCAP0L

CCAP1L

CCAP2L

CCAP3L

CCAP4L

PCA Compare Capture Module 0 H

PCA Compare Capture Module 1

FAh

FBh

PCA Compare Capture Module 2

FCh

FDh

PCA Compare Capture Module 3

FEh

PCA Compare Capture Module 4 H

PCA Compare Capture Module 0 L

PCA Compare Capture Module 1

EAh

EBh

PCA Compare Capture Module 2

ECh

EDh

PCA Compare Capture Module 3

EEh

PCA Compare Capture Module 4 L

CCAP0H7

CCAP1H7

CCAP2H7

CCAP3H7

CCAP4H7

CCAP0L7

CCAP1L7

CCAP2L7

CCAP3L7

CCAP4L7

CCAP0H6

CCAP1H6

CCAP2H6

CCAP3H6

CCAP4H6

CCAP0L6

CCAP1L6

CCAP2L6

CCAP3L6

CCAP4L6

CCAP0H5

CCAP1H5

CCAP2H5

CCAP3H5

CCAP4H5

CCAP0L5

CCAP1L5

CCAP2L5

CCAP3L5

CCAP4L5

CCAP0H4

CCAP1H4

CCAP2H4

CCAP3H4

CCAP4H4

CCAP0L4

CCAP1L4

CCAP2L4

CCAP3L4

CCAP4L4

CCAP0H3

CCAP1H3

CCAP2H3

CCAP3H3

CCAP4H3

CCAP0L3

CCAP1L3

CCAP2L3

CCAP3L3

CCAP4L3

CCAP0H2

CCAP1H2

CCAP2H2

CCAP3H2

CCAP4H2

CCAP0L2

CCAP1L2

CCAP2L2

CCAP3L2

CCAP4L2

CCAP0H1

CCAP1H1

CCAP2H1

CCAP3H1

CCAP4H1

CCAP0L1

CCAP1L1

CCAP2L1

CCAP3L1

CCAP4L1

CCAP0H0

CCAP1H0

CCAP2H0

CCAP3H0

CCAP4H0

CCAP0L0

CCAP1L0

CCAP2L0

CCAP3L0

CCAP4L0

Table 7-8. Interrupt SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

IEN0 A8h Interrupt Enable Control 0 EA EC ET2 ES ET1 EX1 ET0 EX0

IEN1 B1h Interrupt Enable Control 1 EUSB ESPI ETWI EKB

IPL0 B8h Interrupt Priority Control Low 0 PPCL PT2L PSL PT1L PX1L PT0L PX0L

IPH0 B7h Interrupt Priority Control High 0 PPCH PT2H PSH PT1H PX1H PT0H PX0H

IPL1 B2h Interrupt Priority Control Low 1 PUSBL PSPIL PTWIL PKBL

IPH1 B3h Interrupt Priority Control High 1 PUSBH PSPIH PTWIH PKBH

Table 7-9. PLL SFRs

Mnemonic Add Name 7 6 5 4 3 2 1 0

PLLCON A3h PLL Control EXT48 PLLEN PLOCK

PLLDIV A4h PLL Divider R3 R2 R1 R0 N3 N2 N1 N0

Table 7-10. Keyboard SFRs

Mnemonic Add Name 7 6 5 4 3 2 1 0

KBF 9Eh

KBE 9Dh

Keyboard Flag Register

Keyboard Input Enable Register

KBF7 KBF6 KBF5 KBF4 KBF3 KBF2 KBF1 KBF0

KBE7 KBE6 KBE5 KBE4 KBE3 KBE2 KBE1 KBE0

7683C–USB–11/07

AT83C5134/35/36

Table 7-10. Keyboard SFRs

Mnemonic Add Name 7 6 5 4 3 2 1 0

KBLS 9Ch

Keyboard Level Selector Register

KBLS7 KBLS6 KBLS5 KBLS4 KBLS3 KBLS2 KBLS1 KBLS0

Table 7-11. TWI SFRs

Mnemonic Add Name 7 6 5 4 3 2 1 0

SSCON 93h

SSCS 94h

SSDAT 95h

SSADR 96h

Synchronous Serial Control

Synchronous Serial Control-Status

Synchronous Serial Data

Synchronous Serial Address

CR2 SSIE STA STO SI AA CR1 CR0

SC4 SC3 SC2 SC1 SC0 - - -

SD7 SD6 SD5 SD4 SD3 SD2 SD1 SD0

A7 A6 A5 A4 A3 A2 A1 A0

Table 7-12. SPI SFRs

Mnemonic Add Name 7 6 5 4 3 2 1 0

SPCON C3h

SPSTA C4h

Serial Peripheral Control

Serial Peripheral Status-Control

SPR2 SPEN SSDIS MSTR CPOL CPHA SPR1 SPR0

SPIF WCOL SSERR MODF - - - -

SPDAT C5h Serial Peripheral Data R7 R6 R5 R4 R3 R2 R1 R0

Table 7-13. USB SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

USBCON BCh USB Global Control USBE SUSPCLK

USBADDR C6h USB Address FEN UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0

USBINT BDh USB Global Interrupt - - WUPCPU EORINT SOFINT - - SPINT

USBIEN BEh

UEPNUM C7h USB Endpoint Number - - - - EPNUM3 EPNUM2 EPNUM1 EPNUM0

UEPCONX D4h USB Endpoint X Control EPEN - - - DTGL EPDIR EPTYPE1 EPTYPE0

UEPSTAX CEh USB Endpoint X Status DIR RXOUTB1 STALLRQ TXRDY STLCRC RXSETUP RXOUTB0 TXCMP

UEPRST D5h USB Endpoint Reset - - EP5RST EP4RST EP3RST EP2RST EP1RST EP0RST

UEPINT F8h USB Endpoint Interrupt - - EP5INT EP4INT EP3INT EP2INT EP1INT EP0INT

UEPIEN C2h

UEPDATX CFh

USB Global Interrupt Enable

USB Endpoint Interrupt Enable

USB Endpoint X FIFO Data

- -

- - EP5INTE EP4INTE EP3INTE EP2INTE EP1INTE EP0INTE

FDAT7 FDAT6 FDAT5 FDAT4 FDAT3 FDAT2 FDAT1 FDAT0

SDRMWU

EWUPCP

DETACH UPRSM RMWUPE CONFG FADDEN

EEORINT ESOFINT - - ESPINT

7683C–USB–11/07

AT83C5134/35/36

Table 7-13. USB SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

UBYCTLX E2h

UBYCTHX E3h

UFNUML BAh

UFNUMH BBh

USB Byte Counter Low (EP X)

USB Byte Counter High (EP X)

USB Frame Number Low

USB Frame Number High

BYCT7 BYCT6 BYCT5 BYCT4 BYCT3 BYCT2 BYCT1 BYCT0

- - - - - BYCT10 BYCT9 BYCT8

FNUM7 FNUM6 FNUM5 FNUM4 FNUM3 FNUM2 FNUM1 FNUM0

- - CRCOK CRCERR - FNUM10 FNUM9 FNUM8

Table 7-14. Other SFR’s

Mnemonic Add Name 7 6 5 4 3 2 1 0

PCON 87h Power Control SMOD1 SMOD0 - POF GF1 GF0 PD IDL

AUXR 8Eh Auxiliary Register 0 DPU - M0 - XRS1 XRS2 EXTRAM A0

AUXR1 A2h Auxiliary Register 1 - - ENBOOT - GF3 - - DPS

CKCON0 8Fh Clock Control 0 TWIX2 WDX2 PCAX2 SIX2 T2X2 T1X2 T0X2 X2

CKCON1 AFh Clock Control 1 - - - - - - - SPIX2

LEDCON F1h LED Control LED3 LED2 LED1 LED0

7683C–USB–11/07

8. Program/Code Memory

0000h

32 Kbytes

7FFFh

ROM

32 Kbytes

External Code

FFFFh

8000h

0000h

16 Kbytes

3FFFh

ROM

48 Kbytes

External Code

FFFFh

4000h

AT83C5135 AT83C5136

Flash

EPROM

AT89C5131

AD7:0

A15:8

A7:0

A15:8

D7:0

A7:0

ALE

Latch

OEPSEN

The AT83C5134/35/36 implement 16 or 32 Kbytes of on-chip program/code memory. Figure 8-1 shows the split of internal and external program/code memory spaces depending on the product.

Figure 8-1. Program/Code Memory Organization

AT83C5134/35/36

Note: If the program executes exclusively from on-chip code memory (not from external memory),

beware of executing code from the upper byte of on-chip memory and thereby disrupting I/O Ports 0 and 2 due to external prefetch. Fetching code constant from this location does not affect Ports 0 and 2.

8.1 External Code Memory Access

8.1.1 Memory Interface

The external memory interface comprises the external bus (Port 0 and Port 2) as well as the bus control signals (PSEN, and ALE).

Figure 8-2 shows the structure of the external address bus. P0 carries address A7:0 while P2 carries address A15:8. Data D7:0 is multiplexed with A7:0 on P0. Table 8-1 describes the external memory interface signals.

Figure 8-2. External Code Memory Interface Structure

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AT83C5134/35/36

Table 8-1. External Data Memory Interface Signals

ALE

PSEN

PCL

PCHPCH

PCLD7:0 D7:0

PCH

D7:0

CPU Clock

Signal

Name Type Description

A15:8 O

AD7:0 I/O

ALE O

PSEN O

8.1.2 External Bus Cycles

This section describes the bus cycles the AT83C5134/35/36 executes to fetch code (see Figure 8-3) in the external program/code memory.

External memory cycle takes 6 CPU clock periods. This is equivalent to 12 oscillator clock periods in standard mode or 6 oscillator clock periods in X2 mode. For further information on X2 mode (see the clock Section).

For simplicity, the accompanying figure depicts the bus cycle waveforms in idealized form and do not provide precise timing information.

Figure 8-3. External Code Fetch Waveforms

Address Lines

Upper address lines for the external bus.

Address/Data Lines

Multiplexed lower address lines and data for the external memory.

Address Latch Enable

ALE signals indicates that valid address information are available on lines AD7:0.

Program Store Enable Output

This signal is active low during external code fetch or external code read (MOVC instruction).

Alternate Function

P2.7:0

P0.7:0

7683C–USB–11/07

9. AT89C5131 ROM

9.1 ROM Structure

The AT89C5131 ROM memory is divided in two different arrays:

• the code array: 16-32 Kbytes.

• the configuration byte:1 byte.

9.1.1 Hardware Configuration Byte

The configuration byte sets the starting microcontroller options and the security levels.

The starting default options are X1 mode, Oscillator A.

Table 9-1. Hardware Security Byte (HSB)

7 6 5 4 3 2 1 0

- - OSCON1 OSCON0 - - LB1 LB0

AT83C5134/35/36

HSB (S:EFh) Power configuration Register

Number

HSB = xxxx xx11b

9.2 ROM Lock System

The program Lock system, when programmed, protects the on-chip program against software piracy.

Bit

7 - Reserved

6 - Reserved

5-4 OSCON1-0

3 - Reserved

2 - Reserved

1-0 LB1-0

Bit

Mnemonic Description

Oscillator Control Bits

These two bits are used to control the oscillator in order to reduce consumption.

OSCON1 OSCON0 Description

1 1 The oscillator is configured to run from 0 to 32 MHz 1 0 The oscillator is configured to run from 0 to 16 MHz 0 1 The oscillator is configured to run from 0 to 8 MHz 0 0 This configuration shouldn’t be set

User Program Lock Bits

See Table 9-2 on page 28

7683C–USB–11/07

AT83C5134/35/36

9.2.1 Program ROM lock Bits

The lock bits when programmed according to Table 9-2 will provide different level of protection for the on-chip code and data.

Table 9-2. Program Lock bits

Program Lock Bits Protection Description

Security

level LB1 LB0

1 U U No program lock feature enabled.

3 P U Reading ROM data from programmer is disabled.

U: unprogrammed P: programmed

7683C–USB–11/07

10. Stacked EEPROM

10.1 Overview

The AT83C5134/35/36 features a stacked 2-wire serial data EEPROM. The data EEPROM allows to save from 512 Byte for AT24C04 version up to 32 Kbytes for AT24C256 version. The EEPROM is internally connected to the microcontroller on SDA and SCL pins.

10.2 Protocol

In order to access this memory, it is necessary to use software subroutines according to the AT 2 4C x x da t as h ee t . Ne v er t he l es s , be c au se t h e in t e rn al p u ll - u p r e si s to r s of t h e AT83C5134/35/36 is quite high (around 100KΩ), the protocol should be slowed in order to be sure that the SDA pin can rise to the high level before reading it.

Another solution to keep the access to the EEPROM in specification is to work with a software pull-up.

Using a software pull-up, consists of forcing a low level at the output pin of the microcontroller before configuring it as an input (high level).

The C51 the ports are “quasi-bidirectional” ports. It means that the ports can be configured as output low or as input high. In case a port is configured as an output low, it can sink a current and all internal pull-ups are disconnected. In case a port is configured as an input high, it is pulled up with a strong pull-up (a few hundreds Ohms resistor) for 2 clock periods. Then, if the port is externally connected to a low level, it is only kept high with a weak pull up (around 100KΩ), and if not, the high level is latched high thanks to a medium pull (around 10kΩ).

AT83C5134/35/36

Thus, when the port is configured as an input, and when this input has been read at a low level, there is a pull-up of around 100KΩ, which is quite high, to quickly load the SDA capacitance. So in order to help the reading of a high level just after the reading of a low level, it is possible to force a transition of the SDA port from an input state (1), to an output low state (0), followed by a new transition from this output low state to input state; In this case, the high pull-up has been replaced with a low pull-up which warranties a good reading of the data.

7683C–USB–11/07

AT83C5134/35/36

11. On-chip Expanded RAM (ERAM)

ERAM

Upper

128 bytes

Internal

RAM

Lower

128 bytes

Internal

RAM

Special Function Register

80h 80h

0FFh or 3FFh(*)

0FFh

External

Data

Memory

0000

00FFh up to 03FFh (*)

0FFFFh

indirect accesses

direct accesses

direct or indirect

accesses

7Fh

(*) Depends on XRS1..0

The AT83C5134/35/36 provides additional Bytes of random access memory (RAM) space for increased data parameters handling and high level language usage.

AT83C5134/35/36 devices have an expanded RAM in the external data space; maximum size and location are described in Table 11-1.

Table 11-1. Description of Expanded RAM

Address

Part Number ERAM Size

AT83C5134/35/36 1024 00h 3FFh

The AT83C5134/35/36 has on-chip data memory which is mapped into the following four separate segments.

1. The Lower 128 bytes of RAM (addresses 00h to 7Fh) are directly and indirectly addressable.

2. The Upper 128 bytes of RAM (addresses 80h to FFh) are indirectly addressable only.

3. The Special Function Registers, SFRs, (addresses 80h to FFh) are directly addressable only.

4. The expanded RAM bytes are indirectly accessed by MOVX instructions, and with the EXTRAM bit cleared in the AUXR register (see Table 11-1)

The lower 128 bytes can be accessed by either direct or indirect addressing. The Upper 128 bytes can be accessed by indirect addressing only. The Upper 128 bytes occupy the same address space as the SFR. That means they have the same address, but are physically separate from SFR space.

Figure 11-1. Internal and External Data Memory Address

Start End

When an instruction accesses an internal location above address 7Fh, the CPU knows whether the access is to the upper 128 bytes of data RAM or to SFR space by the addressing mode used in the instruction.

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