2.7 LCD drive control circuit
APPLICATION
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3825 GROUP USER’S MANUAL
(2) Ports P0, P10–P15 and P3
When pins P30/SEG18–P37/SEG25, P00/SEG26–P07/SEG33, P10/SEG34–P15/SEG39 are not used as
segment outputs, they can be used as output ports P3 and P0.
Table 2.7.4 shows the setting of output ports P3, P10–P15 and P0.
Ports
Table 2.7.4 Setting of output ports P3, P10–P15 and P0
(3) P3, P10–P15 and P0 pull-down pins
When pins P30/SEG18–P37/SEG25, P00/SEG26–P07/SEG33, P10/SEG34–P15/SEG39 are not used as
ports, it is possible to exert pull-down control. Table 2.7.5 shows the setting of pull-down pins.
Pins
Table 2.7.5 Setting of pull-down pins
P30–P35
P36, P37
P00–P05
P06, P07
P10
P11–P15
Setting
By setting bits 4 and 5 of the segment output enable register (address 003816) to “0,”
next setting bit 0 of the port P1 output control register (address 000316) to “0,” then
setting bit 1 of PULL register A (address 001616) to “1.”
By setting bit 0 of segment output enable register (address 003816) to “0,” then
setting bit 0 of PULL register A (address 001616) to “0.”
By setting bit 1 of segment output enable register (address 003816) to “0,” then
setting bit 0 of PULL register A (address 001616) to “0.”
By setting bit 2 of segment output enable register (address 003816) to “0,” then
setting bit 0 of PULL register A (address 001616) to “0.”
By setting bit 3 of segment output enable register (address 003816) to “0,” then
setting bit 0 of PULL register A (address 001616) to “0.”
By setting bit 4 of segment output enable register (address 003816) to “0,” then
setting bit 0 of port P1 output control register (address 003816) to “1.”
By setting bit 5 of segment output enable register (address 003816) to “0,” then
setting bit 0 of port P1 output control register (address 003816) to “1.”
P30/SEG18–
P37/SEG25
By setting bits 0 and 1 of the segment output enable register (address 003816) to “0,”
then setting bit 0 of PULL register A (address 001616) to “1.”
By setting bits 2 and 3 of the segment output enable register (address 003816) to “0,”
then setting bit 0 of PULL register A (address 001616) to “1.”
P00/SEG26–
P07/SEG33
P10/SEG34–
P15/SEG39