0X5203/0X5213/0X5223/0X5233: Px Port Pull-Up Control Registers (Px_Pu) - Epson S1C17001 Technical Manual

10 INPUT/OUTPUT PORT (P)

0x5203/0x5213/0x5223/0x5233: Px Port Pull-up Control Registers (Px_PU)

Register name Address Bit
P0 Port Pull-up 0x5203 D7–0 P0PU[7:0]
Control Register (8 bits)
(P0_PU)
P1 Port Pull-up 0x5213 D7–0 P1PU[7:0]
Control Register (8 bits)
(P1_PU)
P2 Port Pull-up 0x5223 D7–0 P2PU[7:0]
Control Register (8 bits)
(P2_PU)
P3 Port Pull-up 0x5233 D7–4 –
Control Register (8 bits)
D3–0 P3PU[3:0]
(P3_PU)
Note: The "x" in the bit names indicates the port number (0 to 3).
D[7:0] PxPU[7:0]: Px[7:0] Port Pull-up Enable Bits (P3 port is P3PU[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 select-
ed.
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 re-
sistor. An appropriate wait time must be set for the input/output port loading. The wait time set should
be a value not less than that calculated from the following equation.
Wait time = R
R
IN
C
IN
96
Name Function
P0[7:0] port pull-up enable
P1[7:0] port pull-up enable
P2[7:0] port pull-up enable
reserved
P3[3:0] port pull-up enable
x (C + load capacitance on board) x 1.6 [s]
IN IN
: pull-up resistance maximum value
: pin capacitance maximum value
Setting
1 Enable 0 Disable
1 Enable 0 Disable
1 Enable 0 Disable
–
1 Enable 0 Disable
EPSON
Init. R/W Remarks
1 R/W
(0xff)
1 R/W
(0xff)
1 R/W
(0xff)
– – 0 when being read.
1 R/W
(0xff)
S1C17001 TECHNICAL MANUAL