Rabbit 6000, User Manual

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Rabbit 6000 User’s Manual
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108
10.1.2 Registers
10.2 Dependencies
10.2.1 I/O Pins
Parallel Port C uses pins PC0 through PC7. These pins can be used individually as data inputs or outputs,
as serial port transmit and receive for Serial ports A–F, as clocks for Serial Ports C–F, as external I/O
strobes, or as outputs for the PWM and Timer C peripherals. The input capture peripheral can also watch
pins PC7, PC5, PC3, and PC1.
On startup, PC4, PC2, and PC0 are outputs set high, PC6 is set low, and the other pins are inputs for com-
patibility with the Rabbit 3000.
The individual pins can be set to be open-drain via PCDCR. Drive strength, slew rate, and the pullup/down
resistor status are selectable via PCxCR.
See the associated peripheral chapters for details on how they use Parallel Port C.
10.2.2 Clocks
All outputs on Parallel Port C are clocked by the peripheral clock.
10.2.3 Other Registers
10.2.4 Interrupts
There are no interrupts associated with Parallel Port C.
Register Name Mnemonic I/O Address R/W Reset
Port C Data Register PCDR 0x0050 R/W 00010101
Port C Data Direction Register PCDDR 0x0051 R/W 01010101
Port C Alternate Low Register PCALR 0x0052 R/W 00000000
Port C Alternate High Register PCAHR 0x0053 R/W 00000000
Port C Drive Control Register PCDCR 0x0054 R/W 00000000
Port C Function Register PCFR 0x0055 R/W 00000000
Port Cx Control Register PCxCR x W xxx00000
Register Function
SACR, SBCR, SCCR,
SDCR, SECR, SFCR Select a Parallel Port C pin as serial data (and
optional clock) input.
ICS1R, ICS2R
Select a Parallel Port C pin as a start/stop
condition for Input Capture input.