
17 DMA CONTROLLER
164
EPSON
S1C38000 TECHNICAL MANUAL
bits 31–0
Source address for DMA Channel 1
This is a 32-bit address register for both read and write operation. This register should
be programmed so that the address boundary corresponds correctly with the data
transfer size. For example, for 32-bit transfer, bits 1 and 0 of this register should be
programmed to be 0’s. This register is updated during each transfer cycle by the
specified data transfer size and the source address mode.
bits 31–0
Destination address for DMA Channel 1
This is a 32-bit address register for both read and write operation. This register should
be programmed so that the address boundary corresponds correctly with the data
transfer size. For example, for 32-bit transfer, bits 1 and 0 of this register should be
programmed to be 0’s. This register is updated during each transfer cycle by the
specified data transfer size and the destination address mode.
bits 23–0
Transfer count for DMA Channel 1 Bits [23:0]
This register specifies the number of transfers for the DMA operation and is updated
(decremented) after each transfer. A 0 in this register specifies the maximum transfer
count, which is 224 = 16777216.
bit 17
Acknowledge Mode for DMA Device 1
0
DACK1# becomes active during DMA read cycle
1
DACK1# becomes active during DMA write cycle
bit 16
Acknowledge Level of DACK1# Pin
0
DACK1# is active low
1
DACK1# is active high
Channel 1 Source Address Register
DMA[10h]
Default = xxxx xxxxh
Read/Write
Ch1 Source Address
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Ch1 Source Address
15
14
13
12
11
10
9876543210
Channel 1 Destination Address Register
DMA[14h]
Default =xxxx xxxxh
Read/Write
Ch1 Destination Address
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Ch1 Destination Address
15
14
13
12
11
10
9876543210
Channel 1 Transfer Count Register
DMA[18h]
Default = xxxx xxxxh
Read/Write
n/a
Ch1 Transfer Count
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Ch1 Transfer Count
15
14
13
12
11
10
9876543210
Channel 1 Control Register
DMA[1Ch]
Default = 0000 0000h
Read/Write
n/a
Ack
Mode
Ack Level
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Destination Address
Mode
Source Address
Mode
Resource Select
reserved
Request
Input
Mode
Transmit
Mode
Transfer Size
Interrupt
Enable
Transfer
End
DMA
Enable
15
14
13
12
11
10
9876543210