24 I/O PORTS (GPIO)
S1C33L26 TECHNICAL MANUAL
Seiko Epson Corporation
24-43
USI:
USI_DI, USI_CS, USI_CK
USIL: USIL_DI, USIL_CS, USIL_CK
FSIO: SIN0, SIN1, SCLK0, SCLK1, #SRDY0, #SRDY1
REMC: REMC_I
T16A5: T16A_EXCL_0, T16A_EXCL_1, T16A_ATMA_0, T16A_ATMA_1, T16A_ATMB_0,
T16A_ATMB_1
ADC10: #ADTRIG
GPIO: FPT0–FPTF interrupt ports (See note below.)
When ANFEN is set to 0 (default), the input signals bypass the noise filters.
Notes: • These noise filters cannot be enabled individually.
• The noise filters are not effective if these ports are used as general-purpose input port.
However, the noise filters for the general-purpose input ports that are selected as FPT inter-
rupt ports (FPT0 to FPTF) are effective.
GPIO/PMUX Write Protect Register (GPIO_PROTECT)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
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
D[7:0]
PPROT[7:0]: GPIO/PMUX Register Protect Flag Bits
Enables or disables write protection of the GPIO registers (0x300320–0x30032c and 0x30083e) and
PMUX registers (0x300800–0x300819).
0x96 (R/W):
Disable write protection
Other than 0x96 (R/W): Write-protect the register (default: 0x0)
Before altering any GPIO/PMUX register within addresses 0x300320–0x30032c, 0x300800–0x300819,
and 0x30083e, write data 0x96 to PPROT[7:0] to disable write protection. If PPROT[7:0] is set to other
than 0x96, even if an attempt is made to alter any GPIO/PMUX register by executing a write instruc-
tion, the content of the register will not be altered even though the instruction may have been executed
without a problem. Once PPROT[7:0] is set to 0x96, the GPIO/PMUX registers can be rewritten any
number of times until being reset to other than 0x96. When rewriting the GPIO/PMUX registers has
finished, PPROT[7:0] should be set to other than 0x96 to prevent accidental writing to the GPIO/PMUX
registers.