SAM7S256 Atmel Corporation, SAM7S256 Datasheet - Page 120

• Manufacturer Part Number: SAM7S256
• Manufacturer: Atmel Corporation

Specifications of SAM7S256

• Flash (kbytes): 256 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 55 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• 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): 64
• Self Program Memory: NO
• Dram Memory: No
• Nand Interface: No
• 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: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Coprocessor Interface
4.7
4-16
Undefined instructions
Undefined instructions are treated by the ARM7TDMI processor as coprocessor
instructions. All coprocessors must be absent, CPA and CPB must be HIGH, when an
undefined instruction is presented. The ARM7TDMI processor takes the undefined
instruction trap.
For undefined instructions to be handled correctly, any coprocessors in a system must
give the absent response (CPA and CPB HIGH) to an undefined instruction. This allows
the core to take the undefined instruction exception.
The coprocessor must check bit 27 of the instruction to differentiate between the
following instruction types:
•
•
Coprocessor instructions are not supported in the Thumb instruction set but undefined
instructions are. All coprocessors must monitor the state of the TBIT output from
ARM7TDMI core. When the ARM7TDMI core is in Thumb state, coprocessors must
drive CPA and CPB HIGH, and the instructions seen on the data bus must be ignored.
In this way, coprocessors do not execute Thumb instructions in error, and all undefined
instructions are handled correctly.
undefined instructions have 0 in bit 27
coprocessor instructions have 1 in bit 27.
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ARM DDI 0029G