6 I/O PORTS (PPORT)
S1C17F13 TeChniCal Manual
Seiko epson Corporation
6-7
(Rev. 1.0)
Bits 7–0
P
x
in[7:0]
The GPIO port pin status can be read out from these bits.
1 (R):
Port pin = High level
0 (R):
Port pin = Low level
The port pin status can be read out when input is enabled (P
x
IOEN.P
x
IEN
y
bit = 1). When input is
disabled (P
x
IOEN.P
x
IEN
y
bit = 0), these bits are always read as 0.
When the port is used for a peripheral I/O function, the input value cannot be read out from these bits.
P
x
Port enable Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
P
x
IOEN
15–8 P
x
IEN[7:0]
0x00
H0
R/W –
7–0 P
x
OEN[7:0]
0x00
H0
R/W
*
1: This register is effective when the GPIO function is selected.
*
2: The bit configuration differs depending on the port group.
Bits 15–8 P
x
ien[7:0]
These bits enable/disable the GPIO port input.
1 (R/W): Enable (The port pin status is input.)
0 (R/W): Disable (Input data is fixed at 0.)
When both data output and data input are enabled, the pin output status controlled by this IC can be
read.
These bits do not affect the input control when the port is used as a peripheral I/O function.
Bits 7–0
P
x
Oen[7:0]
These bits enable/disable the GPIO port output.
1 (R/W): Enable (Data is output from the port pin.)
0 (R/W): Disable (The port is placed into Hi-Z.)
These bits do not affect the output control when the port is used as a peripheral I/O function.
P
x
Port Pull-up/down Control Register
Register name
Bit
Bit name
Initial
Reset
R/W
Remarks
P
x
RCTL
15–8 P
x
PDPU[7:0]
0x00
H0
R/W –
7–0 P
x
REN[7:0]
0x00
H0
R/W
*
1: This register is effective when the GPIO function is selected.
*
2: The bit configuration differs depending on the port group.
Bits 15–8 P
x
PDPu[7:0]
These bits select either the pull-up resistor or the pull-down resistor when using a resistor built into
the port.
1 (R/W): Pull-up resistor
0 (R/W): Pull-down resistor
The selected pull-up/down resistor is enabled when the P
x
RCTL.P
x
REN
y
bit = 1.
Bits 7–0
P
x
Ren[7:0]
These bits enable/disable the port pull-up/down control.
1 (R/W): Enable (The built-in pull-up/down resistor is used.)
0 (R/W): Disable (No pull-up/down control is performed.)
Enabling this function pulls up or down the port when output is disabled (P
x
IOEN.P
x
OEN
y
bit = 0).
When output is enabled (P
x
IOEN.P
x
OEN
y
bit = 1), the P
x
RCTL.P
x
REN
y
bit setting is ineffective re-
gardless of how the P
x
IOEN.P
x
IEN
y
bit is set and the port is not pulled up/down.
These bits do not affect the pull-up/down control when the port is used as a peripheral I/O function.