Digi DC-788 - Hardware Description; Microcomputer; Pin Assignment

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17. Hardware Description
17.1. Microcomputer
The H8/3687 Series Microcomputer was chosen for the following reasons:
* Cheaper.
* High-speed CPU with sixteen 16-bit registers.
* 33 interrupt sources and efficient interrupt processing.
* Four versatile timers.
* Two on-chip serial communication interface channels.
* 8-channel 10-bit resolution A/D converter.
*I
2
C bus interface.
* Less chip count.
* Pin compatibility of similar package with difference ROM sizes.
* Instruction set is compatible with the H8/300 CPU.
* Good support.
17.2. Pin Assignment
Pin I/O Assignment Device Remark
P10/TMOW I -
P11/PWM I -
P12 I ACIN AC Power Detects AC Power
P14/IRQ0 I -
P15/IRQ1/TMIB1 I -
P16/IRQ2 I -
P17/IRQ3/TRGV I K0 Keyboard Key Return Line
P20/SCK3 O RTS MAX232 RS-232C
P21/RXD I RXD MAX232 RS-232C
P22/TXD O TXD MAX232 RS-232C
P23 I CTS MAX232 RS-232C
P24 O CVD R12 Device Power Control
P30 O T1 KEYBOARD Key Scanning Line
P31 O T2 KEYBOARD Key Scanning Line
P32 O T3 KEYBOARD Key Scanning Line
P33 O T4 KEYBOARD Key Scanning Line
P34 O T5 KEYBOARD Key Scanning Line
P35 O T6 KEYBOARD Key Scanning Line
P36 I -
P37 I -
P50/WKP0 I -
P51/ WKP 1 I -
P52/ WKP 2 O TBT R8 Controls BATT Detector
P53/ WKP 3 O CVAD R6 Controls BATT Power To A/D
P54 WKP 4 O BTPW R4 Controls BATT Power To M/B
P55/ WKP 5/ADTRG O BTCHG R2 Controls BATT Charger
P56/SDA I/O SDA AT24C128,HMS093AL EEPROM,LCM
P57/SCL O SCL AT24C128,HMS093AL EEPROM,LCM
P60/FTIOA0 O RTCCS 3511A Real Time Clock
P61/FTIOB0 O RTCSCK 3511A Real Time Clock
P62/FTOC0 I/O RTCSIO 3511A Real Time Clock
P63/FTIOD0 O CBUZZ R40 Buzzer Sounder
P64/FTIOA1 O ADCHAN A/D Board Controls A/D Channel
P65/FTIOB1 O ADSCLK A/D Board Controls A/D Conversion
P66/FTIOC1 O ADSDI A/D Board Controls A/D Conversion
P67/FTIOD1 I ADSDO A/D Board Controls A/D Conversion
P70/SCK3_2 I -
P71/RXD_2 I -
P71/TXD_2 I -
P74/TMRIV O EEPWP AT24C128 EEPROM
P75/TMCIV I -
P76/TMOV I -