IP2022 User’s Manual—Peripherals www.ubicom.com 241 To drive the RA1 pin low and the RA0 pin high, the following code
then could be executed: The  second  move  instruction  shown  above  writes  the  RAOUT
register, located at address 0x021. When reading the Port A pins
through the RAIN register (0x020), the upper four bits always read
as zero. When a write is performed to the RxOUT register of a port pin that
has been configured as an input, the write is performed but it has
no immediate effect on the pin. If later that pin is configured as an
output, the pin will be driven with the data that had been previously
written to the RxOUT register. 4.1.6 INTED Register The   INTED   register   consists   of   8   edge   detection   bits   that
correspond to the 8 pins of Port B. A set bit in the INTED register
makes the corresponding port pin trigger on falling edges, while a
clear bit makes the pin trigger on rising edges. 4.1.7 INTF Register The INTF register consists of 8 interrupt flags that correspond to
the 8 pins of Port B. If the trigger condition for a Port B pin occurs, mov w,#0x01 ;load W with the value 01h
;(bits 3:1 low, and bit 0
;high) mov 0x021,w ;write 01h to RAOUT
;register