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17.2 Dependencies
17.2.1 I/O Pins
Serial Port A can transmit on parallel port pins PC6 or PD6, and can receive on pins PC7
or PD7. If the clocked serial mode is enabled, the serial clock is either transmitted or
received on PB1. When an internal clock is selected in the clocked serial mode, PB1 is
automatically enabled as a clock output.
Serial Port B can transmit on parallel port pins PC4 or PD4, and can receive on pins PC5
or PD5. If the clocked serial mode is enabled, the serial clock is either transmitted or
received on PB0. When an internal clock is selected in the clocked serial mode, PB0 is
automatically enabled as a clock output.
Serial Port C can transmit on parallel port pin PC2, and can receive on pin PC3. If the
clocked serial mode is enabled, the serial clock will be on PF1.
Serial Port D can transmit on parallel port pin PC0, and can receive on pin PC1. If the
clocked serial mode is enabled, the serial clock will be transmitted on PF0.
17.2.2 Clocks
The data clocks for Serial Ports A – D are based on the corresponding Timer A output and
can be divided by a Timer A divider. The overall clock divider will be the value in the
appropriate register plus one.
17.2.3 Other Registers
Table 17-2. Pin Usage Serial Ports A – D
Function
Serial Port A
Serial Port B
Serial Port C
Serial Port D
Transmit
PC6, PD6
PC4, PD4
PC2
PC0
Receive
PC7, PD7
PC5, PD5
PC3
PC1
Transmit Clock
PB1
PB0
PF1
PF0
Receive Clock
PB1
PB0
PF1
PF0
Register
Function
TAT4R
Time constant for Serial Port A
TAT5R
Time constant for Serial Port B
TAT6R
Time constant for Serial Port C
TAT7R
Time constant for Serial Port D
PCFR, PDFR
Alternate port output selection