SAM9X25 Atmel Corporation, SAM9X25 Datasheet - Page 32

• Manufacturer Part Number: SAM9X25
• Manufacturer: Atmel Corporation

Specifications of SAM9X25

• Flash (kbytes): 0 Kbytes
• Pin Count: 217
• Max. Operating Frequency: 400 MHz
• Cpu: ARM926
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 105
• Ext Interrupts: 105
• Usb Transceiver: 3
• Usb Speed: Hi-Speed
• Usb Interface: Host, Device
• Spi: 2
• Twi (i2c): 3
• Uart: 7
• Can: 2
• Lin: 4
• Ssc: 1
• Ethernet: 2
• Sd / Emmc: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 10
• Adc Speed (ksps): 440
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: DDR/LPDDR, SDRAM/LPSDR
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 0.9 to 1.1
• Fpu: No
• Mpu / Mmu: No/Yes
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

Table 9-1.
32
32
User and System Mode
CPSR
SAM9X25
SAM9X25
R12
R13
R14
PC
ARM9TDMI Modes and Registers Layout (Continued)
The ARM state register set contains 16 directly-accessible registers, r0 to r15, and an additional
register, the Current Program Status Register (CPSR). Registers r0 to r13 are general-purpose
registers used to hold either data or address values. Register r14 is used as a Link register that
holds a value (return address) of r15 when BL or BLX is executed. Register r15 is used as a pro-
gram counter (PC), whereas the Current Program Status Register (CPSR) contains condition
code flags and the current mode bits.
In privileged modes (FIQ, Supervisor, Abort, IRQ, Undefined), mode-specific banked registers
(r8 to r14 in FIQ mode or r13 to r14 in the other modes) become available. The corresponding
banked registers r14_fiq, r14_svc, r14_abt, r14_irq, r14_und are similarly used to hold the val-
ues (return address for each mode) of r15 (PC) when interrupts and exceptions arise, or when
BL or BLX instructions are executed within interrupt or exception routines. There is another reg-
ister called Saved Program Status Register (SPSR) that becomes available in privileged modes
instead of CPSR. This register contains condition code flags and the current mode bits saved as
a result of the exception that caused entry to the current (privileged) mode.
In all modes and due to a software agreement, register r13 is used as stack pointer.
The use and the function of all the registers described above should obey ARM Procedure Call
Standard (APCS) which defines:
For more details, refer to ARM Software Development Kit.
The Thumb state register set is a subset of the ARM state set. The programmer has direct
access to:
Supervisor Mode
• constraints on the use of registers
• stack conventions
• argument passing and result return
• Eight general-purpose registers r0-r7
• Stack pointer, SP
• Link register, LR (ARM r14)
• PC
• CPSR
SPSR_SVC
R13_SVC
R14_SVC
CPSR
R12
PC
Abort Mode
R13_ABORT
R14_ABORT
SPSR_ABO
CPSR
R12
PC
RT
Undefined Mode
SPSR_UNDEF
R13_UNDEF
R14_UNDEF
CPSR
R12
PC
Interrupt Mode
SPSR_IRQ
R13_IRQ
R14_IRQ
CPSR
Mode-specific banked registers
R12
PC
Fast Interrupt Mode
11054A–ATARM–27-Jul-11
11054A–ATARM–27-Jul-11
SPSR_FIQ
R12_FIQ
R13_FIQ
R14_FIQ
CPSR
PC