28 USB FUNCTION CONTROLLER (USB)
28-58
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
D6
PDREQ
Shows the logic level of the PDREQ signal for monitoring.
D5
PDACK
Shows the logic level of the PDACK signal for monitoring.
D4
Reserved
D3
CounterClr
When this bit is set to 1, the DMA_Count_HH, HL, LH and LL registers are set to 0x00 (to be cleared).
When the DMA_Running bit is 1, writing into this bit is neglected.
D2
Reserved
D1
DMA_Stop
Setting this bit to 1 negates the DMA request (PDREQ) signal. After this bit is set to 1, the DMA_Run-
ning bit is set to 0 (to be cleared) and the DMA_Cmp bit of the DMA_IntStat register is set to 1. When
restarting the DMA transfer, check the DMA_Running bit or the DMA_Cmp bit, and wait until the
DMA operation ends.
Note: Setting this bit to 1 does not stop the DMAC. So to terminate data transfer, first terminate the
DMAC (master) and then set this bit to 1.
D0
DMA_Go
Setting this bit to 1 starts the DMA transfer.
DMA_Config_0 (DMA Configuration 0)
Register name Address
Bit
Name
Setting
Init. R/W
Remarks
DMA_Config_0
(DMA
configuration 0)
0x300c94
(8 bits)
D7
ActivePort
1 Activate DMA port
0 Deactivate DMA port
0
R/W
D6–4 –
–
–
–
0 when being read.
D3
PDREQ_Level
1 Active-low
0 Active-high
0
R/W
D2
PDACK_Level
1 Active-low
0 Active-high
0
R/W
D1
PDRDWR_Level
1 Active-low
0 Active-high
0
R/W
D0
–
–
–
–
0 when being read.
This register sets fields on the bus of the DMA interface.
D7
ActivePort
Sets the DMA interface to “active”.
When this bit is set to 0, the DMA interface signals become “Hi-Z/Don’t care” state.
D[6:4]
Reserved
D3
PDREQ_Level
Sets the PDREQ logic level. Set to 0 (active-high).
D2
PDACK_Level
Sets the PDACK logic level. Set to 0 (active-high).
D1
PDRDWR_Level
Sets the logic levels of the PDRD and PDWR signals. Set to 0 (active-high).
D0
Reserved
DMA_Config_1 (DMA Configuration 1)
Register name Address
Bit
Name
Setting
Init. R/W
Remarks
DMA_Config_1
(DMA
configuration 1)
0x300c95
(8 bits)
D7
RcvLimitMode
1 Receive limit mode
0 Normal
0
R/W
D6–4 –
–
–
–
0 when being read.
D3
SingleWord
1 Single word
0 Multi word
0
R/W
D2–1 –
–
–
–
0 when being read.
D0
CountMode
1 Count-down mode
0 Free-run mode
0
R/W
This register sets fields on the operation mode of the DMA interface.