PBCTL
ADRHEXADRNAMEDescriptionOS
54019$D303PBCTLPort B Controlonly A (400/800)

BitFunctionDescription
7PA7Interrupt status of SIO
6PA6always 0
5PA5always 1
4PA4always 1
3PA3Status of command line of SIO
2PA21=use Port B for data input/output, 0=define data direction, see below
1PA1always 0
0PA0Interrupt of PROCEED line on/off, set to 0 by OS

To define the data direction of PORT B, set Bit 2 of PBCTL to 0. Then write a byte to PORTB, where Bits set to 1 indicate WRITE and Bits set to 0 indicate READ. Normally PORTB is set to %00000000 (=all input).


see also: Controller topics

previous: PACTL

next: DMACTL of ANTIC