Toshiba TMP91C815F Data Book page 46

(4) Detailed description of the Transfer Mode Register
8 bits
DMAM0 to
0 0 0
DMAM3
Number of
Transfer Bytes
000 000
00 Byte transfer
(fixed)
01 Word transfer
10 4-byte transfer
001
00 Byte transfer
01 Word transfer
10 4-byte transfer
010
00 Byte transfer
01 Word transfer
10 4-byte transfer
011
00 Byte transfer
01 Word transfer
10 4-byte transfer
100
00 Byte transfer
01 Word transfer
10 4-byte transfer
101 00 Counter Mode
For counting number of times interrupt is generated
DMASn ← DMASn + 1
DMACn ← DMACn − 1
If DMACn = 0, then INTTCn is generated.
(note1): "n" is the corresponding micro DMA channels 0 to 3
DMADn +/DMASn+ : Post-increment (increment register value after transfer)
DMADn −/DMASn− : Post-decrement (decrement register value after transfer)
The I/Os in the table mean fixed address and the memory means increment(INC) or
decrement(DEC) addresses.
(note2): Execution time is under the condition of:
(note3): Do not use an undefined code for the transfer mode register except for the defined codes listed in the
above table.
(note): When setting a value in this register, write 0 to the upper 3
Mode
bits.
Mode Description
Transfer Destination Address INC Mode
I/O to memory
(DMADn+) ← (DMASn)
DMACn ← DMACn − 1
If DMACn = 0, then INTTCn is generated.
Transfer Destination Address DEC Mod
I/O to memory
(DMADn−) ← (DMASn)
DMACn ← DMACn − 1
If DMACn = 0, then INTTCn is generated.
Transfer Source Address INC Mode
Memory to I/O
(DMADn) ← (DMASn+)
DMACn ← DMACn − 1
If DMACn = 0, then INTTCn is generated.
Transfer Source Address DEC Mode
Memory to I/O
(DMADn) ← (DMASn−)
DMACn ← DMACn − 1
If DMACn = 0, then INTTCn is generated.
Fixed Address Mode
I/O to I/O
(DMADn) ← (DMASn−)
DMACn ← DMACn − 1
If DMACn = 0, then INTTCn is generated.
16bit bus width(both translation and destination address area) / 0 wait /
fc = 16MHz / selected high frequency mode (fc x 1)
91C815-
Number of
Execution States
8 states
12 sates
8 states
12 sates
8 states
12 sates
8 states
12 sates
8 states
12 sates
5 sates
43
TMP91C815
Minimum
Execution Time
@ fc = 16 MHz
1000 ns
1500 ns
1000 ns
1500 ns
1000 ns
1500 ns
1000 ns
1500 ns
1000 ns
1500 ns
625 ns