Rabbit 2000 - Page 63

User’s Manual 57
I/O Strobes
/I0,/I1,
/I2, /I3,
/I4, /I5,
/I6, /I7
Outputs
I/O strobes. Each strobe uses 1/8th of the
I/O space or 8K addresses. Each strobe can
be programmed as: chip select, read, write,
combined read or write. These are
alternate pin assignment for parallel port E,
bits 0–7. Each pin may be individually re-
assigned from parallel port to strobe
functionality.
21–26, 29, 30
External
Interrupt 0
INT0A,
INT0B
Inputs
These pins are sampled and an interrupt
request for external interrupt number 0 is
latched on a specified transition (pos, neg,
either). There is a separate latch for each
pin. May be enabled when this pin is set up
as input for parallel port E. The value of
the pin may also be read via the parallel
port. Uses bits 0, 4 of the parallel port. If
parallel port is set up as output, the parallel
port output may be used to cause the
interrupt.
24, 30
External
Interrupt 1
INT1A,
INT1B
Inputs
These pins are sampled and an interrupt
request for external interrupt number 1 is
latched on a specified transition (pos, neg,
either). There is a separate latch for each
pin. May be enabled when this pin is set up
as input for parallel port E. The value of the
pin may also be read via the parallel port.
Uses bits 1, 5 of the parallel port. If parallel
port is set up as output, the parallel port
output may be used to cause the interrupt.
23, 29
Table 5-1. Rabbit Pin Descriptions (continued)
Pin Group Pin Name Direction Function Pin Numbers