12 i/O PORTS
S1C63003/004/008/016 TeChniCal Manual
Seiko epson Corporation
12-1
(Rev. 1.1)
I/O Ports
12
Configuration of i/O Ports
12.1
The S1C63003/004/008/016 is equipped with I/O ports in which the input/output direction can be switched with
software. Figure 12.1.1 shows the structure of an I/O port.
S1C63016: 24 bits (P00–P03, P10–P13, P20–P23, P30–P33, P40–P43, and P50–P53)
S1C63008: 24 bits (P00–P03, P10–P13, P20–P23, P30–P33, P40–P43, and P50–P53)
S1C63004: 20 bits (P00–P03, P10–P13, P20–P23, P30–P33, and P50–P53)
S1C63003: 16 bits (P00–P03, P10–P13, P20–P23, and P50–P53)
Input
control
Data bus
Pxx
Data
register
I/O control
register (IOC)
Pull-down control
register (PUL)
*
1
*
2
*
1: During output mode
*
2: During input mode
V
SS
V
DD
Mask
option
1.1 Structure of I/O port
Figure 12.
Note: If an output terminal (including a special output terminal) of this IC is used to drive an external com-
ponent that consumes a large amount of current such as a bipolar transistor, design the pattern of
traces on the printed circuit board so that the operation of the external component does not affect
the IC power supply. Refer to "Precautions on Mounting" in the Appendix, for more information.
Each I/O port terminal provides an internal pull-down resistor and it can be connected or disconnected in 1-bit units
by mask option. When "Use" is selected by mask option, the port suits input from the push switch, key matrix, and so
forth. When "Not use" is selected, the port can be used for slide switch input and interfacing with other LSIs.
The P00 and P01 I/O ports can also be used as the Run/Stop and Lap direct inputs for the stopwatch timer
(S1C63004/008/016). The P10 and P22 ports can also be used as the event counter inputs for the programmable
timer.
The I/O port terminals P11–P13 and P23 are shared with the special output (TOUT_A, BZ, FOUT, TOUT_B) ter-
minals, P30–P33 are shared with the serial interface input/output terminals, and P50–P53 are shared with the R/F
converter input/output terminals. The software can select the function to be used. At initial reset, these terminals are
all set to the I/O port.
Table 12.1.1 shows the setting of the input/output terminals by function selection.