Analog Devices SHARC ADSP-214 Series Hardware Reference Manual page 875

Table A-26. AMICTLx Register Bit Descriptions (RW) (Cont'd)
Bit Name
3 PKDIS
4 MSWF
5 ACKEN
10–6 WS
13–11 HC
ADSP-214xx SHARC Processor Hardware Reference
www.BDTIC.com/ADI
Description
Disable Packing/Unpacking.
0 = 8/16-bit data received packed to 32-bit data. Similarly, 32-bit
data to be transmitted is unpacked to four 8-bit data.
1 = 8/16-bit data received zero-filled, for transmitted data only
8-bit LSB part of the 32-bit data is written to external memory.
Note this bit should not be set for bank 0 which is to be used for
instruction fetch.
Most Significant Word First. Applicable only with packing disabled
(PKDIS=0).
0 = 1st 8/16-bit word read/write occupies the least significant posi-
tion in the 32-bit packed word.
1 = 1st 8/16-bit word read/write occupies the most significant posi-
tion in the 32-bit packed word.
Enable the ACK pin. If enabled, reads/writes to devices must be
extended by the corresponding devices by pulling ACK low. When
ACKEN is set, then the ACK pin is sampled after the wait state
value is programmed.
Wait States.
00000 = Reserved (wait state value of 32 if used)
00001 = wait state=1 (only if ACK input used)
00010 = wait state = 2
11111 = Wait state = 31
Wait states and acknowledge signals are used to allow the processors
to connect to memory-mapped peripherals and slower memories.
Wait states are programmable from 1 to 31.
Bus Hold Cycle at the End of Write Access.
000 = Disable bus hold cycle
001 = Hold address for one external port clock cycle
010 = Hold address for two external port clock cycles
A bus hold cycle is an inactive bus cycle that the processor automat-
ically generates at the end of a write to allow a longer hold time for
address and data. Programs may disable holds, or hold off process-
ing for one or more external port processor cycles. Note the address,
data (if a write), and bank select (if in banked external memory)
remain unchanged and are driven for one or more cycles after the
read or write strobes are deasserted.
Registers Reference
A-49