APPENDIX A LIST OF I/O REGISTERS
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
AP-A-9
0x300010–0x300020
Misc Registers (MISC)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
RTC Wait
Control Register
(MISC_RTCWT)
0x300010
(8 bits)
D7–3 –
reserved
–
–
–
0 when being read.
D2–0 RTCWT[2:0] RTC register access wait control
0 to 7 cycles
0x7 R/W Write-protected
USB
Configuration
Register
(MISC_USB)
0x300012
(8 bits)
D7
–
reserved
–
–
–
0 when being read.
D6
USBINTEN USB interrupt enable
1 Enable
0 Disable
0
R/W Write-protected
D5
USBSNZ
USB snooze control
1 Enable
0 Disable
0
R/W
D4–3 –
reserved
–
–
–
0 when being read.
D2–0 USBWT[2:0] USB register access wait control
0 to 7 cycles
0x7 R/W Write-protected
Internal RAM
Wait Control
Register
(MISC_RAMWT)
0x300014
(8 bits)
D7–2 –
reserved
–
–
–
0 when being read.
D1
COREWT
IRAM (12KB) access wait control
1 1 cycle
0 0 cycles
1
R/W Write-protected
D0
BUSWT
IVRAM (20KB) access wait control 1 1 cycle
0 0 cycles
1
R/W
Boot Register
(MISC_BOOT)
0x300016
(8 bits)
D7–4 BOOT[3:0] Boot mode indicator
BOOT[3:0]
Boot mode
*
R
*
Depends on the
BOOT pin status at
initial reset
0b1000
0b0100
Other
SPI/RS232C
NOR/ROM
reserved
D3–2 –
reserved
–
–
–
0 when being read.
D1
BOOT_ENA #CE10 area boot enable
1 Internal
0 External
1
R/W Write-protected
D0
–
reserved
–
–
–
0 when being read.
RAM Location
Select Register
(MISC_RAM_
LOC)
0x300018
(8 bits)
D7–5 –
reserved
–
–
–
0 when being read.
D4
DSTRAM_
CFG
DSTRAM configuration
1 LUTRAM
0 DSTRAM
0
R/W Write-protected
D3–1 –
reserved
–
–
–
0 when being read.
D0
IVRAM_LOC IVRAM location select
1 Area 3
0 Area 0
1
R/W Write-protected
Misc Protect
Register
(MISC_
PROTECT)
0x300020
(8 bits)
D7–0 PROT[7:0] Misc register write-protect flag
Writing 10010110 (0x96)
removes the write protection of
the Misc registers (0x300010–
0x300018).
Writing another value set the
write protection.
0x0 R/W
0x300100–0x300110
Clock Management Unit (CMU)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
Clock Source
Select Register
(CMU_OSCSEL)
0x300100
(8 bits)
D7–2 –
reserved
–
–
–
0 when being read.
D1–0 CLKSEL
[1:0]
System clock source select
CLKSEL[1:0]
Clock source
0x0 R/W Write-protected
0x3
0x2
0x1
0x0
Not allowed
PLL
OSC1
OSC3
Oscillation
Control Register
(CMU_OSCCTL)
0x300101
(8 bits)
D7–4 OSC3WT[3:0] OSC3 wait cycle select
OSC3WT[3:0]
Wait cycle
0xf R/W Write-protected
0xf
0xe
0xd
0xc
0xb
0xa
0x9
0x8
0x7
0x6
0x5
0x4
0x3
0x2
0x1
0x0
128 cycles
256 cycles
512 cycles
1,024 cycles
2,048 cycles
4,096 cycles
8,192 cycles
16,384 cycles
32,768 cycles
65,536 cycles
131,072 cycles
262,144 cycles
524,288 cycles
1,048,576 cycles
2,097,152 cycles
4,194,304 cycles
D3–2 –
reserved
–
–
–
0 when being read.
D1
OSC1EN
OSC1 enable
1 Enable
0 Disable
1
R/W Write-protected
D0
OSC3EN
OSC3 enable
1 Enable
0 Disable
1
R/W