AT91SAM7A3-AU Atmel, AT91SAM7A3-AU Datasheet - Page 116

• Manufacturer Part Number: AT91SAM7A3-AU
• Description: IC ARM7 MCU FLASH 256K 100LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7A3-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 60MHz
• Connectivity: CAN, I²C, MMC, SPI, SSC, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 62
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K 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: 100-LQFP
• Controller Family/series: AT91SAM7xx
• No. Of I/o's: 62
• Ram Memory Size: 32KB
• Cpu Speed: 60MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• Package: 100LQFP
• Device Core: ARM7TDMI
• Family Name: 91S
• Maximum Speed: 60 MHz
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 32 Bit
• Number Of Programmable I/os: 62
• Interface Type: CAN/SPI/I2S/TWI/USART/USB
• On-chip Adc: 2(8-chx10-bit)
• Number Of Timers: 3
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Ram Size: 32 KB
• Maximum Clock Frequency: 60 MHz
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7A3-EK
• Minimum Operating Temperature: - 40 C
• Cpu Family: 91S
• Device Core Size: 32b
• Frequency (max): 60MHz
• Total Internal Ram Size: 32KB
• # I/os (max): 62
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 3V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 100
• Package Type: LQFP
• For Use With: AT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9AT91SAM7A3-EK - KIT EVAL FOR AT91SAM7A3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

21.3
21.3.1
21.3.2
21.3.3
116
Functional Description
AT91SAM7A3 Preliminary
Configuration
Memory Pointers
Transfer Counters
The PDC channels user interface enables the user to configure and control the data transfers
for each channel. The user interface of a PDC channel is integrated into the user interface of
the peripheral (offset 0x100), which it is related to.
Per peripheral, it contains four 32-bit Pointer Registers (RPR, RNPR, TPR, and TNPR) and
four 16-bit Counter Registers (RCR, RNCR, TCR, and TNCR).
The size of the buffer (number of transfers) is configured in an internal 16-bit transfer counter
register, and it is possible, at any moment, to read the number of transfers left for each
channel.
The memory base address is configured in a 32-bit memory pointer by defining the location of
the first address to access in the memory. It is possible, at any moment, to read the location in
memory of the next transfer and the number of remaining transfers. The PDC has dedicated
status registers which indicate if the transfer is enabled or disabled for each channel. The sta-
tus for each channel is located in the peripheral status register. Transfers can be enabled
and/or disabled by setting TXTEN/TXTDIS and RXTEN/RXTDIS in PDC Transfer Control
Register. These control bits enable reading the pointer and counter registers safely without
any risk of their changing between both reads.
The PDC sends status flags to the peripheral visible in its status-register (ENDRX, ENDTX,
RXBUFF, and TXBUFE).
ENDRX flag is set when the PERIPH_RCR register reaches zero.
RXBUFF flag is set when both PERIPH_RCR and PERIPH_RNCR reach zero.
ENDTX flag is set when the PERIPH_TCR register reaches zero.
TXBUFE flag is set when both PERIPH_TCR and PERIPH_TNCR reach zero.
These status flags are described in the peripheral status register.
Each peripheral is connected to the PDC by a receiver data channel and a transmitter data
channel. Each channel has an internal 32-bit memory pointer. Each memory pointer points to
a location anywhere in the memory space (on-chip memory or external bus interface memory).
Depending on the type of transfer (byte, half-word or word), the memory pointer is incre-
mented by 1, 2 or 4, respectively for peripheral transfers.
If a memory pointer is reprogrammed while the PDC is in operation, the transfer address is
changed, and the PDC performs transfers using the new address.
There is one internal 16-bit transfer counter for each channel used to count the size of the
block already transferred by its associated channel. These counters are decremented after
each data transfer. When the counter reaches zero, the transfer is complete and the PDC
stops transferring data.
If the Next Counter Register is equal to zero, the PDC disables the trigger while activating the
related peripheral end flag.
6042E–ATARM–14-Dec-06