PAK-IV Datasheet, PDF (9/14 Pages) List of Unclassifed Manufacturers – Using the PAK-IV I/O Coprocessor

LOW
Forces the specified pin to be an output and outputs a 0 on that pin. Always
returns 0.
OUTPUT
Changes the specified pin to an output. Always returns 0.
PULLON/PULLOFF
These commands enable and disable the weak pull up resistors (about 20K) on the
8 I/O ports associated with BANK A. The default is disabled. The return value is
always 0.
PULSIN0, PULSIN1
Measures low and high pulses. Returns the length, 16-bits, in 2uS units.
PULSOUT
Pulses the output for the specified duration (a 16-bit word specifying 2uS units).
PWM
PWM generates a pulse width train of the specified duty cycle (a byte; 0 is 0%,
255 is 100%) for the alloted time (a 16-bit number in 1ms units).
RCTIME0, RCTIME1
Measures the time for a capacitor to charge or discharge. Returns a zero and the
time in 2uS units (16-bits).
READ
Use this command to read a byte from the PAK-IV's scratch pad RAM. Write the
address (from 0 to $5F) and the return value will be a zero byte, followed by the
data byte.
REVERSE
Changes an input pin to an output pin and vice versa. Always returns 0.
SHIFTIN
ShiftIn requires a single byte argument. The top four bits of this argument specify
the mode. The bottom four bits is the number of bits to shift (1 to 8). The mode
may be any of the following:
0 – MSBPRE (MSB first, sample before clock)
1 – LSBPRE (LSB first, sample before clock)
2 – MSBPOST (MSB first, sample after clock)
3 – LSBPOST (LSB first, sample after clock)
The PAK-IV returns a 0 and the byte shifted in.