AT91SAM9G45-EKES Atmel, AT91SAM9G45-EKES Datasheet - Page 189

• Manufacturer Part Number: AT91SAM9G45-EKES
• Description: KIT EVAL FOR AT91SAM9G45
• Manufacturer: Atmel
• Series: AT91SAM Smart ARMr
• Type: MCUr

Specifications of AT91SAM9G45-EKES

• Contents: Board
• Processor To Be Evaluated: SAM9G45
• Data Bus Width: 32 bit
• Interface Type: I2C, SPI, UART
• Maximum Operating Temperature: + 50 C
• Minimum Operating Temperature: - 10 C
• Operating Supply Voltage: 1.8 V to 3.3 V
• For Use With/related Products: AT91SAM9G45
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q4626953

21.7.2.1
21.7.2.2
6438F–ATARM–21-Jun-10
Byte Write Access
Byte Select Access
Byte write access supports one byte write signal per byte of the data bus and a single read
signal.
Note that the SMC does not allow boot in Byte Write Access mode.
In this mode, read/write operations can be enabled/disabled at a byte level. One byte-select line
per byte of the data bus is provided. One NRD and one NWE signal control read and write.
Figure 21-7
mode, on NCS3 (BAT = Byte Select Access).
• For 16-bit devices: the SMC provides NWR0 and NWR1 write signals for respectively byte0
• For 32-bit devices: NWR0, NWR1, NWR2 and NWR3, are the write signals of byte0 (lower
• For 16-bit devices: the SMC provides NBS0 and NBS1 selection signals for respectively
• For 32-bit devices: NBS0, NBS1, NBS2 and NBS3, are the selection signals of byte0 (lower
(lower byte) and byte1 (upper byte) of a 16-bit bus. One single read signal (NRD) is provided.
byte), byte1, byte2 and byte 3 (upper byte) respectively. One single read signal (NRD) is
provided.
byte0 (lower byte) and byte1 (upper byte) of a 16-bit bus.
byte), byte1, byte2 and byte 3 (upper byte) respectively. Byte Select Access is used to
connect two 16-bit devices.
Byte Write Access is used to connect 2 x 8-bit devices as a 16-bit memory.
Byte Write Access is used to connect 4 x 8-bit devices as a 32-bit memory.
Byte Write option is illustrated on
Byte Select Access is used to connect one 16-bit device.
shows how to connect two 16-bit devices on a 32-bit data bus in Byte Select Access
Figure
21-6.
AT91SAM9G45
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