em78p468l ELAN Microelectronics Corp, em78p468l Datasheet - Page 21

• Manufacturer Part Number: em78p468l
• Description: 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

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