T89C51RD2-3CVC-M View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

T89C51RD2-3CVC-M

0 to 40 MHz Flash Programmable 8-bit Microcontroller

Atmel Corporation 

T89C51RD2

PROGRAM

SIGNALS*

CONTROL

SIGNALS*

4 to 6 MHz

EA

ALE/PROG

RST

PSEN

P2.6

P2.7

P3.3

P3.6

P3.7

XTAL1

+5V

VCC

P0.0-P0.7

D0-D7

P1.0-P1.7

A0-A7

P2.0-P2.5

P3.4

P3.5

VSS

GND

A8-A13

A14

A15

Figure 22. Set-Up Modes Configuration

8.9.4. Programming Algorithm

To program the T89C51RD2 the following sequence must be exercised:

• Check the signature bytes

• Check the HSB (VSB mode)

If the security bits are activated, the following commands must be done before programming:

• Unlock test modes (PEULCK mode, pulse 55h and AAh)

• Chip erase (CERR mode)

• Write FFh in the HSB (PGMS mode)

• Write the signature bytes content in the XAF

• As the boot loader and the XAF content is lost after a "chip erase", it must be reprogrammed if needed.

• Disable programming access (PELCK mode)

To write a page in the FLASH memory, execute the following steps:

• Step 0: Enable programming access (PEULCK mode)

• Step 1: Activate the combination of control signals (PGML mode)

• Step 2: Input the valid address on the address lines (High order bits of the address must be stable during the

complete ALE low time)

• Step 3: Activate the combination of control signals (PGML mode)

• Step 4: Input the appropriate data on the data lines.

• Step 5: Pulse ALE/PROG once.

Repeat step 2 through 5 changing the address and data for end of a 128 bytes page

• Step 6: Enable programming access (PEULCK mode)

• Step 7: Activate the combination of control signals (PGMC mode)

67

Rev. F - 15 February, 2001

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