Port 4 data register (p4dat), Port 4 control register (p4cr) byte write, Bi-directional port 6 – Rainbow Electronics T48C862-R4 User Manual
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T48C862-R4
4551B–4BMCU–02/03
Port 4 Data Register (P4DAT)
Primary register address: "4"hex
Port 4 Control Register (P4CR)
Byte Write
Auxiliary register address: "4"hex
P4xM2, P4xM1 –
Port 4x Interrupt mode/direction code
Bi-directional Port 6
The bi-directional Port 6 is a bitwise configurable I/O port and provides the external pins
for the Timer 3. As a normal port, it performs in exactly the same way as bi-directional
Port 6 (see Figure 32). Two additional multiplexes allow data and port direction control
to be passed over to other internal module (Timer 3). The I/O-pin for T3I line has an
additional mode to generate a Timer 3-interrupt.
All two Port 6 pins can be individually switched by the P6CR register. Figure 32 shows
the internal interfaces to bi-directional Port 6.
Bit 3
Bit 2
Bit 1
Bit 0
P4DAT3
P4DAT2
P4DAT1
P4DAT0
Reset value: 1111b
Bit 3
Bit 2
Bit 1
Bit 0
First write cycle
P41M2
P41M1
P40M2
P40M1
Reset value: 1111b
Bit 7
Bit 6
Bit 5
Bit 4
Second write cycle
P43M2
P43M1
P42M2
P42M1
Reset value: 1111b
Auxiliary Address: "4"hex, First Write
Cycle
Second Write Cycle
Code
3 2 1 0
Function
Code
3 2 1 0
Function
x x 1 1
BP40 in input mode
x x 1 1
BP42 in input mode
x x 1 0
BP40 in output mode
x x 1 0
BP42 in output mode
x x 0 1
BP40 enable alternate function
(SC for SSI)
x x 0 x
BP42 enable alternate function
(T2O for Timer 2)
x x 0 0
BP40 enable alternate function
(falling edge interrupt input for
INT3)
1 1 x x
BP43 in input mode
1 1 x x
BP41 in input mode
1 0 x x
BP43 in output mode
1 0 x x
BP41 in output mode
0 1 x x
BP43 enable alternate function
(SD for SSI)
0 1 x x
BP41 enable alternate function
(VMI for voltage monitor input)
0 0 x x
BP43 enable alternate function
(falling edge interrupt input for
INT3)
0 0 x x
BP41 enable alternate function
(T2I external clock input for
Timer 2)
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