Specifications
Table Of Contents
- Technical Hardware
- 1 OVERVIEW
- 2 POWER SUPPLY AND INITIAL RESET
- 3 CPU, ROM, RAM
- 4 PERIPHERAL CIRCUITS AND OPERATION
- 4.1 Memory Map
- 4.2 Resetting Watchdog Timer
- 4.3 Oscillation Circuit
- 4.4 Input Ports (K00–K03, K10)
- 4.5 Output Ports (R00–R03)
- 4.6 I/O Ports (P00–P03, P10–P13, P20–P23)
- 4.7 LCD Driver (COM0–COM3, SEG0–SEG31)
- 4.8 Clock Timer
- 4.9 Stopwatch Timer
- 4.10 Programmable Timer
- 4.11 Serial Interface (SIN, SOUT, SCLK, SRDY)
- 4.12 A/D Converter
- 4.13 General-purpose Operation Amplifier (AMP)
- 4.14 SVD (Supply Voltage Detection) Circuit
- 4.15 Interrupt and HALT/SLEEP
- 5 SUMMARY OF NOTES
- 6 DIAGRAM OF BASIC EXTERNAL CONNECTIONS
- 7 CHARACTERISTICS
- 8 PACKAGE
- 9 PAD LAYOUT
- Technical Software
- 1 INTRODUCTION
- 2 BLOCK DIAGRAM
- 3 PROGRAM MEMORY (ROM)
- 4 DATA MEMORY
- 5 INITIAL RESET
- 6 PERIPHERAL CIRCUITS
- 6.1 Watchdog Timer
- 6.2 OSC3
- 6.3 Input Ports (K00–K03 and K10)
- 6.4 Output Ports (R00–R03)
- 6.5 I/O Ports (P00–P03, P10–P13 and P20–P23)
- 6.6 LCD Driver
- 6.7 Clock Timer
- 6.8 Stopwatch Timer
- 6.9 Programmable Timer
- 6.10 Serial Interface Circuit
- 6.11 Amplifier
- 6.12 SVD (Supply Voltage Detection) Circuit
- 6.13 A/D Converter
- 6.14 Sleep
- 6.15 Interrupt
- 7 SUMMARY OF NOTES
- APPENDIX
S1C62740 TECHNICAL SOFTWARE EPSON II-31
CHAPTER 6: PERIPHERAL CIRCUITS (I/O Ports)
Serial I/O port
Programming notes
(1) When P20–P23 is used as general I/O ports, set PFS to "0".
(2) When P20–P23 is used as serial I/O ports, set PFS to "1".
(3) When in the input mode, I/O ports are changed from low to
high by pull up resistor, the rise of the waveform is delayed on
account of the time constant of the pull up resistor and input
gate capacitance. Hence, when fetching input ports, set an
appropriate wait time.
Particular care needs to be taken of the key scan during key
matrix configuration.
Make this waiting time the amount of time or more calculated
by the following expression.
10 × C × R
C: terminal capacitance 5 pF + parasitic capacitance ? pF
R: pull up registance 300 kΩ
The I/O port P20–P23 may be set by software as serial I/O port for
the serial interface.
P20: Serial interface data input port (SIN)
P21: Serial interface data output port (SOUT)
P22: Serial interface clock port (SCLK)
P23: Serial interface inverted READY signal (SRDY)
The function of serial interface is explained in Section 6.10.