Rabbit 2000 - Page 62

56 Rabbit 2000 Microprocessor
Power
VBAT +3.0 V (battery backup), +3.3 V or +5.0 V 42
VDD +3.3 V or +5.0 V 3, 28, 53, 78, 92
VSS Ground
2, 27, 39, 52,
77, 89
Serial Ports
CLKA
Input/
Output
Clock for serial port A when operating in
synchronous mode. Alternate assignment
for PB1.
94
CLKB
Input/
Output
Clock for serial port B when operating in
synchronous mode. Alternate assignment
for PB0.
93
RXA, TXA,
RXB, TXB,
RXC, TXC,
RXD, TXD
RX—input
TX—output
Serial inputs and output for serial ports A–
D. These are alternate pin assignments for
parallel port C.
51, 54–60
ARXA,
AT X A ,
ARXB,
AT X B
RX—input
TX—output
Alternate serial inputs and output for serial
ports A and B. These are alternate pin
assignments for parallel port D, PD4–PD7.
43–46
Slave Port
SD0-SD7 Bidirectional
Slave port data bus. An alternate
assignment for parallel port A.
81–88
/SLAVEATT
N
Output
/SLAVEATTN—Slave is requesting
attention from the master. An alternate pin
assignment for parallel port B, bit 7.
100
/SRD Input
Strobe used to read one of the slave
registers. An alternate pin assignment for
parallel port B, bit 3.
96
/SWR Input
Strobe used to write a slave register. An
alternate pin assignment for parallel port B,
bit 2.
95
SA0, SA1 Input
Address lines to address slave registers.
An alternate pin assignment for parallel
port B, bits 4 and 5.
97,98
/SCS Input
Chip select for slave port, active low. An
alternate pin assignment for parallel port E,
bit 7.
21
Table 5-1. Rabbit Pin Descriptions (continued)
Pin Group Pin Name Direction Function Pin Numbers