AT91SAM7SE256B-CUR Atmel, AT91SAM7SE256B-CUR Datasheet - Page 109

• Manufacturer Part Number: AT91SAM7SE256B-CUR
• Description: IC ARM7 MCU FLASH 256K 128-LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7SE256B-CUR

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: EBI/EMI, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 88
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K 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: *
• Processor Series: SAM7SE256
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 32 KB
• Interface Type: SPI, USB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 88
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Operating Temperature Range: - 40 C to + 85 C
• Processor To Be Evaluated: AT91SAM7SE256B
• Supply Current (max): 60 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

19.2.4.4
19.2.4.5
6222F–ATARM–14-Jan-11
General-purpose NVM Bits
Security Bit
General-purpose NVM bits do not interfere with the embedded Flash memory plane. (Does not
apply to EFC1 on the SAM7SE512.) These general-purpose bits are dedicated to protect other
parts of the product. They can be set (activated) or cleared individually. Refer to the product def-
inition section for the general-purpose NVM bit action.
The activation sequence is:
Two errors can be detected in the MC_FSR register after a programming sequence:
It is possible to deactivate a general-purpose NVM bit set previously. The clear sequence is:
Two errors can be detected in the MC_FSR register after a programming sequence:
The Clear General-purpose Bit command programs the general-purpose NVM bit to 0; the corre-
sponding bit GPNVM0 to GPNVMx in MC_FSR reads 0. The Set General-purpose Bit command
programs the general-purpose NVM bit to 1; the corresponding bit GPNVMx in MC_FSR
reads 1.
Note:
The goal of the security bit is to prevent external access to the internal bus system. (Does not
apply to EFC1 on the SAM7SE512.) JTAG, Fast Flash Programming and Flash Serial Test Inter-
face features are disabled. Once set, this bit can be reset only by an external hardware ERASE
request to the chip. Refer to the product definition section for the pin name that controls the
ERASE. In this case, the full memory plane is erased and all lock and general-purpose NVM bits
are cleared. The security bit in the MC_FSR is cleared only after these operations. The activa-
tion sequence is:
• Start the Set General Purpose Bit command (SGPB) by writing the Flash Command Register
• When the bit is set, the bit FRDY in the Flash Programming Status Register (MC_FSR) rises.
• Programming Error: A bad keyword and/or an invalid command have been written in the
• If the general-purpose bit number is greater than the total number of general-purpose bits,
• Start the Clear General-purpose Bit command (CGPB) by writing the Flash Command
• When the clear completes, the bit FRDY in the Flash Programming Status Register
• Programming Error: a bad keyword and/or an invalid command have been written in the
• If the number of the general-purpose bit set in the PAGEN field is greater than the total
• Start the Set Security Bit command (SSB) by writing the Flash Command Register.
with the SEL command and the number of the general-purpose bit to be set in the PAGEN
field.
If an interrupt has been enabled by setting the bit FRDY in MC_FMR, the interrupt line of the
Memory Controller is activated.
MC_FCR register
then the command has no effect.
Register with CGPB and the number of the general-purpose bit to be cleared in the PAGEN
field.
(MC_FSR) rises. If an interrupt has been enabled by setting the bit FRDY in MC_FMR, the
interrupt line of the Memory Controller is activated.
MC_FCR register
number of general-purpose bits, then the command has no effect.
Access to the Flash in read mode is permitted when a Set, Clear or Get General-purpose NVM Bit
command is performed.
SAM7SE512/256/32 Preliminary
109