6 DMA CONTROLLER (DMAC)
6-10
Seiko Epson Corporation
S1C31D50/D51 TECHNICAL MANUAL
(Rev. 2.00)
6.8 Control Registers
DMAC Status Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
DMACSTAT
31–24 –
0x00
–
R
–
23–21 –
0x0
–
R
20–16 CHNLS[4:0]
*
H0
R
*
Number of channels implemented - 1
15–8 –
0x00
–
R
–
7–4 STATE[3:0]
0x0
H0
R
3–1 –
0x0
–
R
0
MSTENSTAT
0
H0
R
Bits 31–21 Reserved
Bits 20–16 CHNLS[4:0]
These bits show the number of DMAC channels implemented in this IC.
Number of channels implemented = CHNLS + 1
Bits 15–8 Reserved
Bits 7–4
STATE[3:0]
These bits indicates the DMA transfer status.
Table 6.8.1 DMA Transfer Status
DMACSTAT.STATE[3:0] bits
DMA transfer status
0xf–0xbf
Reserved
0xa
Peripheral scatter-gather transfer is in progress.
0x9
Transfer has completed.
0x8
Transfer has been suspended.
0x7
Control data is being written.
0x6
Standby for transfer request to be cleared.
0x5
Transfer data is being written.
0x4
Transfer data is being read.
0x3
Transfer destination end pointer is being read.
0x2
Transfer source end pointer is being read.
0x1
Control data is being read.
0x0
Idle
Bits 3–1
Reserved
Bit 0
MSTENSTAT
This bit indicates the DMA controller status.
1 (R):
DMA controller is operating.
0 (R):
DMA controller is idle.
DMAC Configuration Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
DMACCFG
31–24 –
0x00
–
R
–
23–16 –
0x00
–
R
15–8 –
0x00
–
R
–
7–1 –
0x00
–
R
0
MSTEN
–
–
W
Bits 31–1 Reserved
Bit 0
MSTEN
This bit enables the DMA controller.
1 (W):
Enable
0 (W):
Disable