st2032a Sitronix Technology Corporation, st2032a Datasheet - Page 17

• Manufacturer Part Number: st2032a
• Description: 8 Bit Microcontroller With 32k Bytes Rom
• Manufacturer: Sitronix Technology Corporation

10.3 Port-B and Port-C
10.3.1 General Description
Ver 2.4
Port-B and Port-C are bit-programmable bi-direction I/O ports,
controlled by PCB and PCC registers. There is also bit
programmable pull-up resistor for each input pin. All of the 16
10.3.2 Input/Output Control
PCB/PCC controls the I/O direction of Port-B/C. Each bit of
PCB[7~0]/PCC[7~0] controls the direction of one single bit of
10.3.3 PORT-B and PORT-C PULL-UP OPTION
Port-B/C contains PMOS transistors of pull-up resistor
controlled by software in bit-manner. In case of input
direction, on/off of the pull-up PMOS transistor is
controlled by the data wrote to data register, PB/PC. “ 1”
is for enable and “ 0” is for disable. Above all, whole
pull-up control is by PULL bit of PMCR. Refer to
FIGURE 10-4 for the block description.
Address Name
Address Name
Address Name
Address Name
$00A
$00A
$001
$002
$009
$00F
$039
$009
$00F
Bit 7~0: PCB[7~0] : Port-B directional bits
Bit 7~0: PCC[7~0] : Port-C directional bits
Bit 7: PULL : Enable all pull-up functions bit
PCC
PCC
PB
PC
PCB
PMCR
LSEL
PCB
PMCR
1 = Enable pull-up function
0 = Disable pull-up function
1 = Output mode
0 = Input mode
1 = Output mode
0 = Input mode
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
PCB[7]
PCC[7]
PCB[7]
PCC[7]
PC[7]
PULL
PULL
PB[7]
Bit 7
Bit 7
Bit 7
Bit 7
-
TABLE 10-6 Summary of Port-B AND Port-C Registers
PCC[6]
PCC[6]
PCB[6]
PCB[6]
PDBN
PDBN
PB[6]
PC[6]
TABLE 10-7 PORT-B Control Register (PCB)
TABLE 10-8 PORT-C Control Register (PCC)
Bit 6
Bit 6
Bit 6
Bit 6
TABLE 10-9 Port Control Register (PMCR)
-
PCC[5]
PCC[5]
PCB[5]
INTEG
PCB[5]
INTEG
PB[5]
PC[5]
Bit 5
Bit 5
Bit 5
Bit 5
-
LSEL[4] LSEL[3] LSEL[2] LSEL[1] LSEL[0]
17/54
PCC[4]
PCC[4]
PCB[4]
PCB[4]
PB[4]
PC[4]
Bit 4
Bit 4
Bit 4
Bit 4
PULL-UP
-
-
PORT
CONTROL
REGISTER
( PCR )
PORT
DATA
REGISTER
( PDR )
I/Os can change into LCD segment drives. Control register
LSEL specifies which of these I/Os are LCD drives.
Port-B/C respectively, with “ 1” for output mode, and “ 0” for input
mode.
FIGURE 10-4 Port-B and Port-C Block Diagram
PCB[3]
PCC[3]
PCB[3]
PCC[3]
PC[3]
PB[3]
Bit 3
Bit 3
Bit 3
Bit 3
-
-
DATA INPUT
PCB[2]
PCC[2]
PCB[2]
PCC[2]
PC[2]
PB[2]
Bit 2
Bit 2
Bit 2
Bit 2
-
-
PCB[1]
PCC[1]
PCB[1]
PCC[1]
PB[1]
PC[1]
Bit 1
Bit 1
Bit 1
Bit 1
RD_INPUT
-
-
VCC
PCB[0]
PCC[0]
PCB[0]
PCC[0]
PULL-UP
PB[0]
PC[0]
Bit 0
Bit 0
Bit 0
Bit 0
PMOS
-
-
100 - - - - -
100 - - - - -
0000 0000
0000 0000
0000 0000
0000 0000
- - - 1 1111
1111 1111
1111 1111
Default
Default
Default
Default
ST2032A
9/13/07