R40008 Atmel Corporation, R40008 Datasheet - Page 11

• Manufacturer Part Number: R40008
• Manufacturer: Atmel Corporation

Specifications of R40008

• Flash (kbytes): 0 Kbytes
• Pin Count: 100
• Max. Operating Frequency: 75 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 256
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.3
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• 32khz Rtc: No
• Calibrated Rc Oscillator: No

8. Peripherals
8.0.1
8.0.2
8.0.3
1732FS–ATARM–12-Apr-06
Peripheral Registers
Peripheral Interrupt Control
Peripheral Data Controller
The AT91R40008 microcontroller peripherals are connected to the 32-bit wide Advanced
Peripheral Bus. Peripheral registers are only word accessible – byte and half-word accesses
are not supported. If a byte or a half-word access is attempted, the memory controller auto-
matically masks the lowest address bits and generates a word access.
Each peripheral has a 16-Kbyte address space allocated (the AIC only has a 4-Kbyte address
space).
The following registers are common to all peripherals:
Unused bits in the peripheral registers are shown as “–” and must be written at 0 for upward
compatibility. These bits read 0.
The Interrupt Control of each peripheral is controlled from the Status Register using the inter-
rupt mask. The Status Register bits are ANDed to their corresponding interrupt mask bits and
the result is then ORed to generate the Interrupt Source signal to the Advanced Interrupt
Controller.
The interrupt mask is read in the Interrupt Mask Register and is modified with the Interrupt
Enable Register and the Interrupt Disable Register. The enable/disable/status (or mask)
makes it possible to enable or disable peripheral interrupt sources with a non-interruptible sin-
gle instruction. This eliminates the need for interrupt masking at the AIC or Core level in real-
time and multi-tasking systems.
The AT91R40008 microcontroller has a 4-channel PDC dedicated to the two on-chip USARTs.
One PDC channel is dedicated to the receiver and one to the transmitter of each USART.
The user interface of a PDC channel is integrated in the memory space of each USART. It
contains a 32-bit Address Pointer Register (RPR or TPR) in addition to a 16-bit Transfer
Counter Register (RCR or TCR). When the programmed number of transfers are performed, a
status bit indicating the end of transfer is set in the USART Status Register and an interrupt
can be generated.
• Control Register – write-only register that triggers a command when a one is written to the
• Mode Register – read/write register that defines the configuration of the peripheral. Usually
• Data Registers – read and/or write registers that enable the exchange of data between the
• Status Register – read-only register that returns the status of the peripheral.
• Enable/Disable/Status Registers are shadow command registers. Writing a one in the
corresponding position at the appropriate address. Writing a zero has no effect.
has a value of 0x0 after a reset.
processor and the peripheral.
Enable Register sets the corresponding bit in the Status Register. Writing a one in the
Disable Register resets the corresponding bit and the result can be read in the Status
Register. Writing a bit to zero has no effect. This register access method maximizes the
efficiency of bit manipulation and enables modification of a register with a single non-
interruptible instruction, replacing the costly read-modify-write operation.
AT91R40008
11