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DS80C400 Network Microcontroller
30 of 96
PIN NAME
FUNCTION
59 A13
58 A14
57 A15
P2.2
A10 Program/Data Memory Address 10
P2.3
A11 Program/Data Memory Address 11
P2.4
A12 Program/Data Memory Address 12
P2.5
A13 Program/Data Memory Address 13
P2.6
A14 Program/Data Memory Address 14
P2.7
A15 Program/Data Memory Address 15
20 P3.0
21 P3.1
22 P3.2
23 P3.3
24 P3.4
25 P3.5
26 P3.6
27 P3.7
Port 3, I/O.
Port 3 functions as an 8-bit, bidirectional I/O port, and as an alternate interface for several resources
found on the traditional 8051. The reset condition of Port 3 is all bits at logic 1 through a weak pullup. The logic
1 state also serves as an input mode, since external circuits writing to the port can override the weak pullup.
When software clears any port pin to 0, the device activates a strong pulldown that remains on until either a 1 is
written to the port pin or a reset occurs. Writing a 1 after the port has been at 0 activates a strong transition
driver, followed by a weaker sustaining pullup. Once the momentary strong driver turns off, the port once again
becomes the output (and input) high state.
Port Alternate
Function
P3.0
RXD0 Serial Port 0 Receive
P3.1
TXD0 Serial Port 0 Transmit
P3.2
INT0
External Interrupt 0
P3.3
INT1
External Interrupt 1
P3.4
T0 Timer 0 External Input
P3.5
T1/CLKO Timer 1 External Input/External Clock Output
P3.6
WR
External Data Memory Write Strobe
P3.7
RD
External Data Memory Read Strobe
48 P4.0
47 P4.1
46 P4.2
45 P4.3
44 P4.4
43 P4.5
42 P4.6
41 P4.7
Port 4, I/O.
Port 4 can function as an 8-bit, bidirectional I/O port, and as the source for external address and
chip-enable signals for program and data memory. Port pins are configured as I/O or memory signals through
the P4CNT register. The reset condition of Port 4 is all bits at logic 1 through a weak pullup. The logic 1 state
also serves as an input mode, since external circuits writing to the port can override the weak pullup. When
software clears any port pin to 0, the device activates a strong pulldown that remains on until either a 1 is written
to the port pin or a reset occurs. Writing a 1 after the port has been at 0 activates a strong transition driver,
followed by a weaker sustaining pullup. Once the momentary strong driver turns off, the port once again
becomes the output (and input) high state.
Port Alternate
Function
P4.0
CE0
Program Memory Chip Enable 0
P4.1
CE1
Program Memory Chip Enable 1
P4.2
CE2
Program Memory Chip Enable 2
P4.3
CE3
Program Memory Chip Enable 3
P4.4
A16 Program/Data Memory Address 16
P4.5
A17 Program/Data Memory Address 17
P4.6
A18 Program/Data Memory Address 18
P4.7
A19 Program/Data Memory Address 19
35 P5.0
34 P5.1
33 P5.2
32 P5.3
31 P5.4
30 P5.5
29 P5.6
28 P5.7
Port 5, I/O.
Port 5 can function as an 8-bit, bidirectional I/O port, the CAN interface, Timer 3 input, and/or as
peripheral-enable signals. The reset condition of Port 5 is all bits at logic 1 through a weak pullup. The logic 1
state also serves as an input mode, since external circuits writing to the port can override the weak pullup.
When software clears any port pin to 0, the device activates a strong pulldown that remains on until either a 1 is
written to the port pin or a reset occurs. Writing a 1 after the port has been at 0 activates a strong transition
driver, followed by a weaker sustaining pullup. Once the momentary strong driver turns off, the port once again
becomes the output (and input) high state.
Port Alternate
Function
P5.0
C0TX CAN0 Transmit Output
P5.1
C0RX CAN0 Receive Input
P5.2
T3 Timer 3 External Input
P5.3 None
P5.4
PCE0
Peripheral Chip Enable 0
P5.5
PCE1
Peripheral Chip Enable 1
P5.6
PCE2
Peripheral Chip Enable 2
P5.7
PCE3
Peripheral Chip Enable 3
56 P6.0
55 P6.1
54 P6.2
53 P6.3
52 P6.4
Port 6, I/O.
Port 6 can function as an 8-bit, bidirectional I/O port, as program and data memory address/chip-
enable signals, and/or a third serial port. The reset condition of Port 6 is all bits at logic 1 through a weak pullup.
The logic 1 state also serves as an input mode, since external circuits writing to the port can override the weak
pullup. When software clears any port pin to 0, the device activates a strong pulldown that remains on until
either a 1 is written to the port pin or a reset occurs. Writing a 1 after the port has been at 0 activates a strong
transition driver, followed by a weaker sustaining pullup. Once the momentary strong driver turns off, the port
once again becomes the output (and input) high state.
Port Alternate
Function
P6.0
CE4
Program Memory Chip Enable 4
Содержание DS80C400
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