34.9.2.2 Byte Select Access
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 signal and one NWE signal control read and write.
- For 16-bit devices: the SMC provides NBS0 and NBS1 selection signals
for respectively byte0 (lower byte) and byte1 (upper byte) of a 16-bit bus.
Byte Select Access is used to connect one 16-bit device.
- For 32-bit devices: NBS0, NBS1, NBS2 and NBS3 are the selection signals of byte0 (lower byte), byte1, byte2 and byte 3 (upper byte) respectively. Byte Select Access is used to connect two 16-bit devices.
Figure 34-7 shows how to connect two 16-bit devices on a 32-bit data bus in Byte Select Access mode, on NCS3 (BAT = Byte Select Access).
