EM78P468N/EM78P468L
8-Bit Microcontroller
Product Specification
(V1.5) 02.15.2007
•
15
(This specification is subject to change without further notice)
6.2 Special Purpose Registers
6.2.1 A
(Accumulator)
Internal data transfer operation, or instruction operand holding usually involves the
temporary storage function of the Accumulator, which is not an addressable register.
Registers of IOC Page 0 (IOC50 ~ IOCF0, Bit 0 of R5 = “0”)
6.2.2
IOC50/P5CR (Port 5 I/O and Ports 7, 8 for LCD Segment Control
Register)
(Address: 05h, Bit 0 of R5 = “0”)
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
IOC57 IOC56 IOC55 IOC54 P8HS P8LS P7HS P7LS
Bits 7~4 (IOC57~54):
Port 5 I/O direction control register
IOC5x = “0”:
set the relative P5.x I/O pins as output
IOC5x = “1”:
set the relative P5.x I/O pin into high impedance (input pin)
Bit 3 (P8HS):
Switch to high nibble I/O of Port 8 or to LCD segment output while
sharing
pins with SEGxx/P8.x pins.
P8HS = “0”:
select high nibble of Port 8 as normal P8.4~P8.7
P8HS = “1”:
select LCD segment output as SEG 28~SEG 31 output
Bit 2 (P8LS):
Switch to low nibble I/O of Port 8 or to LCD segment output while sharing
pins with SEGxx/P8.x pins
P8LS = ”0”:
select low nibble of Port 8 as normal P8.0~P8.3
P8LS = ”1”:
select LCD Segment output as SEG 24~SEG 27 output
Bit 1 (P7HS):
Switch to high nibble I/O of Port 7 or to LCD segment output while
sharing
pins with SEGxx/P7.x pins
P7HS = “0”:
select high nibble of Port 7 as normal P7.4~P7.7
P7HS = “1”:
select LCD Segment output as SEG 20~SEG 23 output
Bit 0 (P7LS):
Switch to low nibble I/O of Port 7 or to LCD segment output while sharing
pins with SEGxx/P7.x pins
P7LS = “0”:
select low nibble of Port 7 as normal P7.0~P7.3
P7LS = “1”:
select LCD segment output as SEG 16~SEG 19 output