AT91SAM7X128 Atmel, AT91SAM7X128 Datasheet - Page 133

• Manufacturer Part Number: AT91SAM7X128
• Description: MCU 32-Bit 91S ARM7TDMI RISC 128KB Flash 1.8V/3.3V 100-Pin LQFP
• Manufacturer: Atmel

Specifications of AT91SAM7X128

• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 55 MHz
• Ram Size: 32 KB
• Program Memory Size: 128 KB
• Operating Supply Voltage: 1.8|3.3 V
• Data Bus Width: 32 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 62
• Interface Type: CAN/Ethernet/SPI/I2S/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 3

20.3.4.6
20.3.4.7
20.3.4.8
6120H–ATARM–17-Feb-09
Flash Security Bit Command
AT91SAM7X512 Select EFC Command
Memory Write Command
Security bits can be set using Set Security Bit command (SSE). Once the security bit is active,
the Fast Flash programming is disabled. No other command can be run. Only an event on the
Erase pin can erase the security bit once the contents of the Flash have been erased.
The AT91SAM7X512 security bit is controlled by the EFC0. To use the Set Security Bit com-
mand, the EFC0 must be selected using the Select EFC command.
Table 20-27. Set Security Bit Command
Once the security bit is set, it is not possible to access FFPI. The only way to erase the security
bit is to erase the Flash.
In order to erase the Flash, the user must perform the following:
Then it is possible to return to FFPI mode and check that Flash is erased.
The commands WPx, EA, xLB, xFB are executed using the current EFC controller. The default
EFC controller is EFC0. The Select EFC command (SEFC) allows selection of the current EFC
controller.
Table 20-28. Select EFC Command
This command is used to perform a write access to any memory location.
The Memory Write command (WRAM) is optimized for consecutive writes. An internal address
buffer is automatically increased.
Table 20-29. Write Command
Read/Write
Write
Step
1
2
Read/Write
Write
Write
Write
Write
Write
Write
• Power-off the chip
• Power-on the chip with TST = 0
• Assert Erase during a period of more than 220 ms
• Power-off the chip
Handshake Sequence
Write handshaking
Write handshaking
DR Data
SSE
DR Data
(Number of Words to Write) << 16 | (WRAM)
Address
Memory [address]
Memory [address+4]
Memory [address+8]
Memory [address+(Number of Words to Write - 1)* 4]
AT91SAM7X512/256/128 Preliminary
MODE[3:0]
CMDE
DATA
DATA[15:0]
SEFC
0 = Select EFC0
1 = Select EFC1
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