APPENDIX A LIST OF I/O REGISTERS
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
AP-A-25
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
PC[3:0] Port
Function Select
Register
(PMUX_PC_03)
0x300818
(8 bits)
D7–6 CFPC3[1:0] PC3 port function select
CFPC3[1:0]
Function
0x0 R/W Write-protected
0x3
0x2
0x1
0x0
reserved
reserved
PC3
D11
D5–4 CFPC2[1:0] PC2 port function select
CFPC2[1:0]
Function
0x0 R/W
0x3
0x2
0x1
0x0
reserved
reserved
PC2
D10
D3–2 CFPC1[1:0] PC1 port function select
CFPC1[1:0]
Function
0x0 R/W
0x3
0x2
0x1
0x0
reserved
reserved
PC1
D9
D1–0 CFPC0[1:0] PC0 port function select
CFPC0[1:0]
Function
0x0 R/W
0x3
0x2
0x1
0x0
reserved
reserved
PC0
D8
PC[7:4] Port
Function Select
Register
(PMUX_PC_47)
0x300819
(8 bits)
D7–6 CFPC7[1:0] PC7 port function select
CFPC7[1:0]
Function
0x0 R/W Write-protected
0x3
0x2
0x1
0x0
reserved
reserved
PC7
D15
D5–4 CFPC6[1:0] PC6 port function select
CFPC6[1:0]
Function
0x0 R/W
0x3
0x2
0x1
0x0
reserved
reserved
PC6
D14
D3–2 CFPC5[1:0] PC5 port function select
CFPC5[1:0]
Function
0x0 R/W
0x3
0x2
0x1
0x0
reserved
reserved
PC5
D13
D1–0 CFPC4[1:0] PC4 port function select
CFPC4[1:0]
Function
0x0 R/W
0x3
0x2
0x1
0x0
reserved
reserved
PC4
D12
Port Noise
Filter Control
Register
(GPIO_FILTER)
0x30083e
(8 bits)
D7–1 –
reserved
–
–
–
0 when being read.
D0
ANFEN
Input port noise filter enable
1 Enable
0 Disable
0
R/W Write-protected
GPIO/PMUX
Write Protect
Register
(GPIO_
PROTECT)
0x30083f
(8 bits)
D7–0 PPROT[7:0] GPIO/PMUX register protect flag Writing 10010110 (0x96)
removes the write protection of
the GPIO registers (0x300320–
0x30032c and 0x30083e) and
PMUX registers (0x300800–
0x300819). Writing another
value set the write protection.
0x0 R/W
0x300400–0x300472
USI
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
USI Global
Configuration
Register
(USI_GCFG)
0x300400
(8 bits)
D7–4 –
reserved
–
–
–
0 when being read.
D3
LSBFST
MSB/LSB first mode select
1 MSB first
0 LSB first
0
R/W
D2–0 USIMOD
[2:0]
Interface mode configuration
USIMOD[2:0]
I/F mode
0x0 R/W
0x7–0x6
0x5
0x4
0x3
0x2
0x1
0x0
reserved
I
2
C slave
I
2
C master
SPI slave
SPI master
UART
Software reset
USI
Transmit Data
Buffer Register
(USI_TD)
0x300401
(8 bits)
D7–0 TD[7:0]
USI transmit data buffer
TD7 = MSB
TD0 = LSB
0x0 to 0xff
0x0 R/W
USI Receive
Data Buffer
Register
(USI_RD)
0x300402
(8 bits)
D7–0 RD[7:0]
USI receive data buffer
RD7 = MSB
RD0 = LSB
0x0 to 0xff
0x0
R