
10 Input/Output Port (P)
S1C17003 TECHNICAL MANUAL
EPSON
10-13
IOPort
0x5203/0x5213/0x5223/0x5233/0x5234: Px Port Pull-up Control Registers (Px_PU)
Register name Address
Bit
Name
Function
Setting
Init. R/W
Remarks
P0 Port Pull-up
Control Register
(P0_PU)
0x5203
(8 bits)
D7–0 P0PU[7:0]
P0[7:0] port pull-up enable
1 Enable
0 Disable
1
(0xff)
R/W
P1 Port Pull-up
Control Register
(P1_PU)
0x5213
(8 bits)
D7–0 P1PU[7:0]
P1[7:0] port pull-up enable
1 Enable
0 Disable
1
(0xff)
R/W
P2 Port Pull-up
Control Register
(P2_PU)
0x5223
(8 bits)
D7–0 P2PU[7:0]
P2[7:0] port pull-up enable
1 Enable
0 Disable
1
(0xff)
R/W
P3 Port Pull-up
Control Register
(P3_PU)
0x5233
(8 bits)
D7–0 P3PU[7:0]
P3[7:0] port pull-up enable
1 Enable
0 Disable
1
(0xff)
R/W
P4 Port Pull-up
Control Register
(P4_PU)
0x5243
(8 bits)
D7–4 –
reserved
–
1 when being read.
D3–0 P4PU[3:0]
P4[3:0] port pull-up enable
1 Enable
0 Disable
1
(0xff)
R/W
Note: The “x” in the bit names indicates the port number (0 to 4).
D[7:0]
PxPU[7:0]: Px[7:0] Port Pull-up Enable Bits (P4 port is P4PU[3:0])
Enable or disable the pull-up resistor included in each port.
1 (R/W): Enabled (default)
0 (R/W): Disabled
PxPU[7:0] are the pull-up control bits that correspond directly to the Px[7:0] ports. Setting to 1 enables
the pull-up resistor and pulls up the port pin in input mode. It will not be pulled up if set to 0.
The PxPU[7:0] setting is disabled in output mode, and the pin is not pulled up.
Input/output ports that are not used should be set with pull-up enabled.
This pull-up setting is also enabled for ports for which the peripheral module function has been
selected.
A delay will occur in the waveform rise-up depending on time constants such as pull-up resistance and
pin load capacitance if the port pin is switched from Low level to High level by the internal pull-up
resistor. Therefore, an appropriate wait time must be set for loading an input/output port.
The P25 and P26 pins are not present. Settings onto the register are therefore disabled.