HT48CXX/HT48RXX
Pin Description of HT48C70
Pin Name I/O
Mask
Option
Function
PA0~PA7
I/O
Wake-up
Pull-high
or None
Bidirectional 8-bit input/output ports
Each bit can be configured as a wake-up input by mask option.
Software instructions determine the CMOS output or schmitt
trigger input with or without pull high resistor (by mask option).
PB0~PB7
I/O
Pull-high
or None
Bidirectional 8-bit input/output ports
Software instructions determine the CMOS output or schmitt
trigger input (pull-high depends on mask option).
VSS
—
—
Negative power supply, GND
INT
I
—
External interrupt schmitt trigger with pull high resistor
Edge trigger is activated during high to low transition.
TMR0
I
—
Schmitt trigger input for timer/event counter 0
TMR1
I
—
Schmitt trigger input for timer/event counter 1
PC0~PC7
I/O
Pull-high
or None
Bidirectional 8-bit input/output ports
Software instructions determine the CMOS output or schmitt
trigger input (pull-high depends on mask option).
RES
I
—
Schmitt trigger reset input, active low
VDD
—
—
Positive power supply
OSC1
OSC2
I
O
Crystal or
RC
OSC1 and OSC2 are connected to an RC network or a crystal
(by mask option) for the internal system clock. In the case of RC
operation, OSC2 is the output terminal for 1/4 system clock.
PD0~PD7
I/O
Pull-high
or None
Bidirectional 8-bit input/output ports
Software instructions determine the CMOS output or schmitt
trigger input (pull-high depends on mask option).
PE0~PE7
I/O
Pull-high
or None
Bidirectional 8-bit input/output ports
Software instructions determine the CMOS output or schmitt
trigger input (pull-high depends on mask option).
PF0~PF7
I/O
Pull-high
or None
Bidirectional 8-bit input/output ports
Software instructions determine the CMOS output or schmitt
trigger input (pull-high depends on mask option).
PG0~PG7
I/O
Pull-high
or None
Bidirectional 8-bit input/output ports
Software instructions determine the CMOS output or schmitt
trigger input (pull-high depends on mask option).
9
25th May ’99