AT91SAM7A1-AU Atmel, AT91SAM7A1-AU Datasheet - Page 31

• Manufacturer Part Number: AT91SAM7A1-AU
• Description: IC ARM7 MCU 32BIT ROMLESS144LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7A1-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 40MHz
• Connectivity: CAN, EBI/EMI, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 49
• Program Memory Type: ROMless
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-LQFP
• For Use With: AT91SAM7A1-EK - BOARD EVAL FOR AT91SAM7A1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -

10.3.4.3
6048B–ATARM–29-Jun-06
16-bit Access Device Connection
Figure 10-5. EBI Connection for External 2x8-bit Memory Devices, 8-bit or 16-bit Access
A typical 16-bit memory device connection with 16-bit access only is shown in
In this case, the AT91SAM7A1 is in byte write access mode and boots on the 16-bit memory.
NWR1 and NWR0 are used by the EBI but only NWR0 is used by the memory, enabling a 16-
bit access.
The correct mode for this configuration is byte select access and should be set in the boot.
• The signal NWR0/NWE is used as NWR0 and enables lower byte writes.
• The signal NRD/NOE is used as NRD and enables half-word and byte reads.
• The signal A0/NLB is not used.
• The signal NWR1/NUB is not used.
• The signal NWR0/NWE is used as NWR0 and enables half-word writes.
• The signal NRD/NOE is used as NRD and enables half-word and byte reads.
EBI
D[15:0]
A[21:1]
NWR0
NWR1
NRD
NCS
D[15:0] D[7:0]
D[15:8]
External Memory
External Memory
D[7:0]
A[20:0]
NWE
NOE
NCE
D[7:0]
A[20:0]
NWE
NOE
NCE
(MSB)
(LSB)
8-Bit
8-Bit
AT91SAM7A1
Figure
10-6.
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