AT91SAM7S256C-MU Atmel, AT91SAM7S256C-MU Datasheet - Page 134

• Manufacturer Part Number: AT91SAM7S256C-MU
• Description: IC ARM7 MCU 32BIT 256K 64-QFN
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7S256C-MU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, DMA, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 64K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VQFN Exposed Pad, 64-HVQFN, 64-SQFN, 64-DHVQFN
• Processor Series: AT91
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 64 KB
• Interface Type: SPI, TWI, USART, USB
• Maximum Clock Frequency: 55 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 5
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7S-EK - KIT EVAL FOR ARM AT91SAM7S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: AT91SAM7S256-MU; AT91SAM7S256-MU

20.2.5.7
20.2.5.8
134
AT91SAM7S Series Preliminary
AT91SAM7S512 Select EFC Command
Memory Write Command
The AT91SAM7S512 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 20-15. 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 o 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 20-16. 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. Write handshaking
can be chained; an internal address buffer is automatically increased.
Table 20-17. Write Command
Step
1
2
Step
1
2
Step
1
2
3
4
5
...
n
n+1
• 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
Handshake Sequence
Write handshaking
Write handshaking
Handshake Sequence
Write handshaking
Write handshaking
Write handshaking
Write handshaking
Write handshaking
...
Write handshaking
Write handshaking
MODE[3:0]
CMDE
ADDR0
ADDR1
DATA
DATA
...
ADDR0
ADDR1
MODE[3:0]
CMDE
DATA
MODE[3:0]
CMDE
DATA
DATA[15:0]
WRAM
Memory Address LSB
Memory Address
*Memory Address++
*Memory Address++
...
Memory Address LSB
Memory Address
DATA[15:0]
SEFC
0 = Select EFC0
1 = Select EFC1
DATA[15:0]
SSE
0
6175K–ATARM–30-Aug-10