Jameco Electronics Rabbit 3000 - Manual (Page 143)

134 Rabbit 3000 Microprocessor
Figure 9-1. Parallel Port D Block Diagram
PD7
PD4
I/O Data perclk/2
Timer A1
Timer B1
Timer B2
perclk/2
Timer A1
Timer B1
Timer B2
PD3
PD0
ATXA
ATXB
ARXA
ARXB
PD5
PD6
inputs
Driver—optional open drain