EM78P468LAQ EMC [ELAN Microelectronics Corp], EM78P468LAQ Datasheet - Page 56

• Manufacturer Part Number: EM78P468LAQ
• Description: 8-BIT Microcontroller
• Manufacturer: EMC [ELAN Microelectronics Corp]

EM78P468L
8-BIT Microcontroller
52 •
4.12
• Bit 3 (HLP): Power consumption selection. If your system usually runs in green mode, it
must be set to low power consumption to help support the energy saving issue. We
recommend that low power consumption mode is slected.
Bit 2~0 (PR2~PR0): Protect Bit
PR2~PR0 are protect bits as explained below:
Instruction Set
Each instruction in the instruction set is a 13-bit word divided into an OP code and one or
more operands. Normally, all instructions are executed within one single instruction cycle
(one instruction consists of 2 oscillator periods), unless the program counter is changed
by instruction "MOV R2,A", "ADD R2,A", or by instructions of arithmetic or logic operation
on R2 (e.g. "SUB R2,A", "BS(C) R2,6", "CLR R2", ⋅⋅⋅⋅ ). In this case, the execution takes
two instruction cycles.
If for some reasons, the specification of the instruction cycle is not suitable for certain
applications, try modifying the instruction as follows :
Execute within two instruction cycles the "JMP", "CALL", "RET", "RETL", & "RETI"
instructions, or the conditional skip instructions ("JBS", "JBC", "JZ", "JZA", "DJZ",
"DJZA") which were tested to be true. Also execute within two instruction cycles the
instructions that are written to the program counter.
Additionally, the instruction set offers the following features :
(1) Every bit of any register can be set, cleared, or tested directly.
(2) The I/O register can be regarded as general register. That is, the same instruction
The symbol "R" represents a register designator that specifies which one of the registers
(including operational registers and general purpose registers) is to be utilized by the
instruction. "b" represents a bit field designator that selects the value for the bit that is
located in the register "R", and affects operation. "k" represents an 8 or 10-bit constant or
literal value.
can operate on I/O register.
HLP = “0”: Low power consumption mode
HLP = “1”: High power consumption mode
PR2
1
Others
PR1
1
(This specification is subject to change without further notice)
PR0
1
Product Specification (V1.0) 03.15.2006
Protect
Disable
Enable