SAM7SE256 Atmel Corporation, SAM7SE256 Datasheet - Page 26

• Manufacturer Part Number: SAM7SE256
• Manufacturer: Atmel Corporation

Specifications of SAM7SE256

• Flash (kbytes): 256 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 48 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 88
• Ext Interrupts: 88
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 3
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

8.1.2.5
8.1.2.6
8.1.3
26
SAM7SE512/256/32
Fast Flash Programming Interface
Non-volatile Brownout Detector Control
Calibration Bits
The 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 200 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.
Sixteen NVM bits are used to calibrate the brownout detector and the voltage regulator. These
bits are factory configured and cannot be changed by the user. The ERASE pin has no effect on
the calibration bits.
The Fast Flash Programming Interface allows programming the device through either a serial
JTAG interface or through a multiplexed fully-handshaked parallel port. It allows gang-program-
ming with market-standard industrial programmers.
The FFPI supports read, page program, page erase, full erase, lock, unlock and protect
commands.
The Fast Flash Programming Interface is enabled and the Fast Programming Mode is entered
when the TST pin and the PA0 and PA1 pins are all tied high and PA2 tied to low.
• GPNVM bit 0 is used as a brownout detector enable bit. Setting the GPNVM bit 0 enables the
• GPNVM bit 1 is used as a brownout reset enable signal for the reset controller. Setting the
• The Flash of the SAM7SE512 is organized in 2048 pages of 256 bytes (dual plane). It reads
• The Flash of the SAM7SE256 is organized in 1024 pages of 256 bytes (single plane). It reads
• The Flash of the SAM7SE32 is organized in 256 pages of 128 bytes (single plane). It reads
• The Flash of the SAM7SE512/256 contains a 256-byte write buffer, accessible through a 32-
• The Flash of the SAM7SE32 contains a 128-byte write buffer, accessible through a 32-bit
BOD, clearing it disables the BOD. Asserting ERASE clears the GPNVM bit 0 and thus
disables the brownout detector by default.
GPNVM bit 1 enables the brownout reset when a brownout is detected, Clearing the GPNVM
bit 1 disables the brownout reset. Asserting ERASE disables the brownout reset by default.
as 131,072 32-bit words.
as 65,536 32-bit words.
as 32,768 32-bit words.
bit interface.
interface.
6222F–ATARM–14-Jan-11