Table of Contents
Advertisement
12 i/O PORTS
iOC0[3:0]: P0 port i/O control register (FF21h)
iOC1[3:0]: P1 port i/O control register (FF25h)
iOC2[3:0]: P2 port i/O control register (FF29h)
iOC3[3:0]: P3 port i/O control register (FF2Dh) – S1C63004/008/016
iOC4[3:0]: P4 port i/O control register (FF31h) – S1C63008/016
iOC5[3:0]: P5 port i/O control register (FF35h)
Sets the I/O ports to input or output mode.
When "1" is written: Output mode
When "0" is written: Input mode
Reading: Valid
The input/output mode of the I/O ports are set in 1-bit units. Writing "1" to the I/O control register places the
corresponding I/O port into output mode, and writing "0" sets input mode. At initial reset, these registers are all
set to "0," so the I/O ports are placed in input mode.
The I/O control register of the port, which is set for an input/output of the serial interface or R/F converter or a
special output, are ineffective.
Pul0[3:0]: P0 port pull-down control register (FF22h)
Pul1[3:0]: P1 port pull-down control register (FF26h)
Pul2[3:0]: P2 port pull-down control register (FF2ah)
Pul3[3:0]: P3 port pull-down control register (FF2eh) – S1C63004/008/016
Pul4[3:0]: P4 port pull-down control register (FF32h) – S1C63008/016
Pul5[3:0]: P5 port pull-down control register (FF36h)
Enables the pull-down during input mode.
When "1" is written: Pull-down On
When "0" is written: Pull-down Off
Reading: Valid
These registers enable the built-in pull-down resistor to be effective during input mode in 1-bit units. (The pull-
down resistor is included into the ports selected by mask option.)
By writing "1" to the pull-down control register, the corresponding I/O ports are pulled down during input mode,
while writing "0" or output mode disables the pull-down function. At initial reset, these registers are all set to "1,"
so the pull-down function is enabled.
The pull-down control register of the port in which the pull-down resistor is not included becomes a general-
purpose register. The register of the port that is set as output for the serial interface, input/output for the R/F con-
verter or a special output can also be used as a general-purpose register that does not affect the pull-down control.
The pull-down control register of the port that is set as input for the serial interface functions the same as the I/O
port.
SMT0[3:0]: P0 port input interface level select register (FF23h)
SMT1[3:0]: P1 port input interface level select register (FF27h)
Selects an input interface level.
When "1" is written: CMOS Schmitt level
When "0" is written: CMOS level
Reading: Valid
These registers select the input interface level of the P0 and P1 I/O ports in 1-bit units. When "1" is written to
SMTxx, the corresponding I/O port Pxx is configured with a CMOS Schmitt level input interface. When "0" is
written, the port is configured with a CMOS level input interface. At initial reset, these registers are set to "1."
The input interface level of the P2 to P5 ports are fixed at a CMOS Schmitt level.
12-8
Seiko epson Corporation
S1C63003/004/008/016 TeChniCal Manual
(Rev. 1.1)
Advertisement
Table of Contents
