24 I/O PORTS (GPIO)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
24-25
D3
Reserved
D[2:0]
SCTPE[2:0]: FPTE Chattering Filter Time Select Bits
Configures the chattering filter circuit for the FPTE port.
See the descriptions of SCTP0[2:0]/GPIO_FPT01_CHAT register.
Port DMA Trigger Source Select Register (GPIO_DMA)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
Port DMA
Trigger Source
Select Register
(GPIO_DMA)
0x30034c
(8 bits)
D7–4 –
reserved
–
–
–
0 when being read.
D3–0 SPTRG[3:0] Port DMA trigger source select
SPTRG[3:0]
Trigger source 0x0 R/W
0xf
0xe
0xd
0xc
0xb
0xa
0x9
0x8
0x7
0x6
0x5
0x4
0x3
0x2
0x1
0x0
FPTF
FPTE
FPTD
FPTC
FPTB
FPTA
FPT9
FPT8
FPT7
FPT6
FPT5
FPT4
FPT3
FPT2
FPT1
FPT0
D[7:4]
Reserved
D[3:0]
SPTRG[3:0]: Port DMA Trigger Source Select Bits
Selects an FPT port as a DMA trigger source to invoke DMA transfer.
8.8 DMA Trigger Source Selection
Table 24.
SPTRG[3:0]
Trigger source
SPTRG[3:0]
Trigger source
0xf
FPTF
0x7
FPT7
0xe
FPTE
0x6
FPT6
0xd
FPTD
0x5
FPT5
0xc
FPTC
0x4
FPT4
0xb
FPTB
0x3
FPT3
0xa
FPTA
0x2
FPT2
0x9
FPT9
0x1
FPT1
0x8
FPT8
0x0
FPT0
(Default: 0x0)
The interrupt signal of the selected FPT line, which is generated according to the interrupt mode and
polarity settings regardless of the SIET
n
setting (even if the interrupt is disabled), is sent to the DMAC
to trigger a DMA transfer. For more information on DMA transfer, see the “DMA Controller (DMAC)”
chapter.
Note: After setting GPIO_FPT
nn
_CHAT register, the port may send an undesired DMA trigger to the
DMAC. Disable the port DMA request for at least the wait time shown below after the GPIO_
FPT
nn
_CHAT register is set.
Wait time [µs] = Filter sampling time [µs]
×
4
Example: When the filter sampling time is 64/f
PCLK2
and f
PCLK2
= 32 MHz
Wait time = 64
×
4 / 32 = 8 [µs]
The port DMA function can be used after waiting 8 µs or more when the GPIO_FPT
nn
_
CHAT register is set to 0x7.