LC877816A_08 Datasheet, PDF (9/21 Pages) Sanyo Semicon Device – 8-bit 1-chip Microcontroller

LC877816A/12A/08A
Port Output Types
Port form and pull-up resistor options are shown in the following table.
Port status can be read even when port is set to output mode.
Port Name
P00 to P07
Option Selected
in Units of
1 bit
Option Type
1
CMOS
Output Type
Pull-up Resistor
Programmable(Note 1)
2
Nch-open drain
No
P10 to P17
1 bit
1
CMOS
Programmable
2
Nch-open drain
Programmable
P70
-
No
Nch-open drain
Programmable
P71 to P73
-
No
CMOS
Programmable
S16(PC0) to
-
1
CMOS
No
S23(PC7)
2
Pch-open drain
3
Nch-open drain
Note 1: Attachment of Port0 programmable pull-up resistors is controllable in nibble units (P00 to 03, P04 to 07).
*1: Connect as follows to reduce noise on VDD.
VSS1 and VSS2 must be connected together and grounded.
Power
supply
LSI
VDD1
VDD2
V1
V2
V3
VDC
CUP1
CUP2
Back up capacitors *2 ^{VSS1 VSS2}
*2: The power supply for the internal memory is VDC. VDD1 and VDD2 are used as the power supply for ports.
When VDD1 and VDD2 are not backed up, the port level does not become “H” even if the port latch is in the “H”
level. Therefore, when VDD1 and VDD2 are not backed up and the port latch is “H” level, the port level is unstable
in the HOLD mode, and the back up time becomes shorter because the through current runs from VDD to GND in
the input buffer. If VDD1 and VDD2 are not backed up, output “L” by the program or pull the port to “L” by the
external circuit in the HOLD mode so that the port level becomes “L” level and unnecessary current consumption is
prevented.
No.A0635-9/21