DS80C390_00 Datasheet, PDF (34/155 Pages) Dallas Semiconductor – High-Speed Microcontroller User’s Guide Supplement

DS80C390 High-Speed Microcontroller User’s Guide Supplement
Port 5 Control Register (P5CNT)
7
6
5
4
3
2
1
0
SFR A2h CAN1BA CAN0BA SP1EC C1_I/O C0_I/O P5CNT.2 P5CNT.1 P5CNT.0
RW-0 RW-0 RW-0 RW-0 RW-0
RT-1
RT-1
RT-1
R=Unrestricted Read, W=Unrestricted Write, T=Timed Access Write Only, -n=Value after Reset
CAN1BA
Bit 7
CAN0BA
Bit 6
SP1EC
Bit 5
C1_I/O
Bit 4
C0_I/O
Bit 3
CAN 1 Bus Active. The CAN1BA signal is a latched status bit that will be
set if the respective CAN1 I/O Enabled (P5CNT.4) bit is set and bus activity
detected on the CAN 1 bus. Once activity is detected and the bit is set, it will
remain set until cleared via application software or a reset.
CAN 0 Bus Active. The CAN0BA signal is a latched status bit that will be
set if the respective CAN0 I/O Enabled (P5CNT.3) bit is set and bus activity
detected on the CAN 0 bus. Once activity is detected and the bit is set, it will
remain set until cleared via application software or a reset.
Serial Port 1 External Connections. This bit controls whether the Serial
Port 1 signals are asserted on P1.2/P1.3 or P5.2/P5.3. Rerouting the serial
port signals to Port 5 allows the use of both serial ports (but with the loss of
the CAN 1 interface) when Port 1 becomes a dedicated address bus during
demultiplexed addressing mode. Note that the corresponding port pins must
be set to 1 before they can be used in their serial port or CAN functions.
0 = Serial Port 1 signals are routed to P1.2/P1.3.
Conditions: MUX =0, SFR bit P1.2 =1, SFR bit P1.3 =1
1 = Serial Port 1 signals are routed to P5.2/P5.3
Conditions: MUX =0, SFR bit P5.2 =1, SFR bit P5.3 =1
CAN 1 I/O Enable. This bit controls the function of port pins P5.2 and P5.3.
0 = Port pins P5.2 and P5.3 function as general-purpose I/O pins. The alternate
Serial Port 1 transmit and receive functions on Port 5 are only possible when
this bit is cleared to 0.
1 = Port pins P5.2 and P5.3 are dedicated to the CAN 1 receive and transmit
functions.
CAN 0 I/O Enable. This bit controls the function of port pins P5.0 and P5.1.
0 = Port pins P5.0 and P5.1 function as general-purpose I/O pins.
1 = Port pins P5.0 and P5.1 are dedicated to the CAN 0 receive and transmit
functions.
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