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16.2 Dependencies
16.2.1 I/O Pins
Serial Port A can transmit on parallel port pins PC7, PC6, or PD6, and can receive on pins
PC7, PD7, or PE7. If the clocked serial mode is enabled, the serial clock is either transmit-
ted 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 PC5, PC4, or PD4, and can receive on pins
PC5, PD5, or PE5. If the clocked serial mode is enabled, the serial clock is either transmit-
ted 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 pins PC3 or PC2, and can receive on pins PC3,
PD3, or PE3. If the clocked serial mode is enabled and 8-bit memories are used, the serial
clock will be transmitted on PD2, and can be received on either PD2 or PE2. The serial
clock may also be transmitted on PC7, PD7, or PE7. When 16-bit memories are used, the
serial clock can be transmitted on PC7 or PE7, and can be received on PD2 or PE2.
NOTE: When Serial Port C is used as a clocked serial port and 8-bit memories are used,
the serial clock is transmitted on PD2, and so PD2 will not be available for other use.
Serial Port D can transmit on parallel port pins PC1 or PC0, and can receive on pins PC1,
PD1, or PE1. If the clocked serial mode is enabled and 8-bit memories are used, the serial
clock will be transmitted on PD0, and can be received on either PD0 or PE0. The serial
clock may also be transmitted on PC3, PD3, or PE3. When 16-bit memories are used, the
serial clock can be transmitted on PC3 or PE3, and can be received on PD0 or PE0.
NOTE: When Serial Port D is used as a clocked serial port and 8-bit memories are used,
the serial clock is transmitted on PD0, and so PD0 will not be available for other use.
Table 16-2. Pin Usage Serial Ports A – D
Function
Serial Port A
Serial Port B
Serial Port C
Serial Port D
Transmit
PC7, PC6, PD6
PC5, PC4, PD4
PC3, PC2
PC1, PC0
Receive
PC7, PD7, PE7
PC5, PD5, PE5
PC3, PD3, PE3
PC1, PD1, PE1
Transmit Clock
PB1
PB0
PD2
(PC7, PD7, PE7)*
* The options in parentheses may be used in addition to PD2 or PD0 for the corresponding serial
port. One of the highlighted pins not on Parallel Port D must be used for the clocked output
when you are using the serial port in the clocked serial mode and you are using 16-bit memories.
PD0
Receive Clock
PB1
PB0
PD2, PE2
PD0, PE0