AT91SAM7S321-AU Atmel, AT91SAM7S321-AU Datasheet - Page 24

• Manufacturer Part Number: AT91SAM7S321-AU
• Description: IC ARM7 MCU FLASH 32K 64LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7S321-AU

• 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: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 8K 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-LQFP
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 8 KB
• Interface Type: I2C, I2S, SPI, SSC, TWI, UART, USB
• Maximum Clock Frequency: 55 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 10 bit
• Operating Supply Voltage: 1.8 V to 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, KSK-AT91SAM7S-PL, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7S-EK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Controller Family/series: AT91SAM7xxxx
• No. Of I/o's: 32
• Ram Memory Size: 8KB
• Cpu Speed: 55MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• 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: Lead free / RoHS Compliant

8.7.3.5
Table 8-1.
8.7.4
8.7.5
24
Device
AT91SAM7S512
AT91SAM7S256
AT91SAM7S128
AT91SAM7S64
AT91SAM7S321/32
AT91SAM7S Series Preliminary
Security Bit Feature
Non-volatile Brownout Detector Control
AT91SAM7S321/32
Flash Configuration Summary
Asserting the ERASE pin clears the lock bits, thus unlocking the entire Flash.
The Embedded Flash Controller manages 8 lock bits to protect 8 regions of the flash against
inadvertent flash erasing or programming commands. The AT91SAM7S321/32 contains 8 lock
regions and each lock region contains 32 pages of 128 bytes. Each lock region has a size of 4
Kbytes.
If a locked-region’s erase or program command occurs, the command is aborted and the EFC
trigs an interrupt.
The 8 NVM bits are software programmable through the EFC User Interface. The command
“Set Lock Bit” enables the protection. The command “Clear Lock Bit” unlocks the lock region.
Asserting the ERASE pin clears the lock bits, thus unlocking the entire Flash.
Table 8-1
The AT91SAM7S Series features a security bit, based on a specific NVM Bit. When the secu-
rity is enabled, any access to the Flash, either through the ICE interface or through the Fast
Flash Programming Interface, is forbidden. This ensures the confidentiality of the code pro-
grammed in the Flash.
This security bit can only be enabled, through the Command “Set Security Bit” of the EFC
User Interface. Disabling the security bit can only be achieved by asserting the ERASE pin at
1, and after a full flash erase is performed. When the security bit is deactivated, all accesses to
the flash are permitted.
It is important to note that the assertion of the ERASE pin should always be longer than
50 ms.
As the ERASE pin integrates a permanent pull-down, it can be left unconnected during normal
operation. However, it is safer to connect it directly to GND for the final application.
Two general purpose NVM (GPNVM) bits are used for controlling the brownout detector
(BOD), so that even after a power loss, the brownout detector operations remain in their state.
These two GPNVM bits can be cleared or set respectively through the commands “Clear Gen-
eral-purpose NVM Bit” and “Set General-purpose NVM Bit” of the EFC User Interface.
• GPNVM Bit 0 is used as a brownout detector enable bit. Setting the GPNVM Bit 0 enables
the BOD, clearing it disables the BOD. Asserting ERASE clears the GPNVM Bit 0 and thus
disables the brownout detector by default.
Number of Lock Bits
32
16
8
16
8
summarizes the configuration of the six devices.
Number of Pages in the Lock Region
64
64
64
32
32
Page Size
256 bytes
256 bytes
256 bytes
128 bytes
128 bytes
6175G–ATARM–22-Nov-06