AT91SAM7A1-AU Atmel, AT91SAM7A1-AU Datasheet - Page 30

• 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
10.3.4.1
10.3.4.2
30
AT91SAM7A1
Byte Write Access (BAT = 0)
8-bit Access Device Connection
8-bit or 16-bit Access Device Connection
Figure 10-3. EBI Connection for External 16-bit Memory Devices, 8-bit or 16-bit Access
This mode is selected by setting the bit BAT to 0 in AMC_CSRx registers and is typically used
to connect 2 x 8-bit devices as a 16-bit memory page. This is the mode selected at reset on
NCS0.
In this mode, users can interface the EBI with one or two 8-bit memories.
If the EBI is interfaced with two 8-bit memories, the users have the choice of either an 8-bit or
a 16-bit access.
A typical 8-bit memory device connection with 8-bit access is shown in
DBW[1:0] should be for a 8-bit-data bus width and only NWR0 is used
Figure 10-4. EBI Connection for External 8-bit Memory Device, 8-bit Access Only
A typical 2 x 8-bit memory device connection with 8-bit or 16-bit access is shown in
5.
• The signal A0/NLB is used as A0.
• The signal NWR1/NUB is not used.
• The signal NWR0/NWE is used as NWR0 and enables lower byte writes.
• The signal NRD/NOE is used as NRD and enables byte reads.
• The signal A0/NLB is not used.
• The signal NWR1/NUB is used as NWR1 and enables upper byte writes.
EBI
EBI
A[21:0]
NWR0
D[15:0]
A[21:1]
D[7:0]
NRD
NCS
NUB
NWE
NCS
NOE
NLB
External Memory
External Memory
D[15:0]
A[20:0]
NLB
NUB
NWE
NOE
NCE
D[7:0]
A[21:0]
NWE
NOE
NCE
16-bit
8-bit
Figure
6048B–ATARM–29-Jun-06
10-4.
Figure 10-