10 INPUT/OUTPUT PORT (P)
86
EPSON
S1C17001 TECHNICAL MANUAL
10.4 Pull-up Control
The input/output port contains a pull-up resistor, which you can choose to use or not use individually for each bit
using the P
x
PU[7:0] (P
x
_PU register).
∗
P0PU[7:0]
: P0[7:0] Port Pull-up Enable Bits in the P0 Port Pull-up Control (P0_PU) Register (D[7:0]/0x5203)
∗
P1PU[7:0]
: P1[7:0] Port Pull-up Enable Bits in the P1 Port Pull-up Control (P1_PU) Register (D[7:0]/0x5213)
∗
P2PU[7:0]
: P2[7:0] Port Pull-up Enable Bits in the P2 Port Pull-up Control (P2_PU) Register (D[7:0]/0x5223)
∗
P3PU[3:0]
: P3[3:0] Port Pull-up Enable Bits in the P3 Port Pull-up Control (P3_PU) Register (D[3:0]/0x5233)
Setting P
x
PU[7:0] to 1 (default) 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 P
x
PU[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. 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 calcu-
lated from the following equation.
Wait time = R
IN
x (C
IN
+ load capacitance on board) x 1.6 [s]
R
IN
: pull-up resistance maximum value
C
IN
: pin capacitance maximum value
Summary of Contents for S1C17001
Page 1: ...Technical Manual S1C17001 CMOS 16 BIT SINGLE CHIP MICROCONTROLLER ...
Page 33: ...4 POWER SUPPLY VOLTAGE 24 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 63: ...6 INITERRUPT CONTROLLER 54 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 87: ...8 CLOCK GENERATOR CLG 78 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 91: ...9 PRESCALER PSC 82 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 133: ...11 16 BIT TIMER T16 124 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 211: ...16 STOPWATCH TIMER SWT 202 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 219: ...17 WATCHDOG TIMER WDT 210 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 241: ...18 UART 232 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 277: ...20 I2 C 268 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...
Page 313: ...25 PACKAGE 304 EPSON S1C17001 TECHNICAL MANUAL This page intentionally left blank ...