PIC16C662-20/TQ Microchip Technology, PIC16C662-20/TQ Datasheet - Page 74

• Manufacturer Part Number: PIC16C662-20/TQ
• Description: 8-Bit EPROM Microcontrollers with Analog Comparators
• Manufacturer: Microchip Technology

PIC16C64X & PIC16C66X
10.1
The PIC16C64X & PIC16C66X’s orthogonal instruction
set allows read and write of all file registers, including
special function registers. There are some special situ-
ations the user should be aware of:
10.1.1
If an instruction writes to STATUS, the Z, C, and DC bits
may be set or cleared as a result of the instruction and
overwrite the original data bits written. For example,
executing CLRF STATUS will clear register STATUS,
and then set the Z bit leaving 0000 0100b in the reg-
ister.
10.1.2
Read, write or read-modify-write on PCL may have the
following results:
Read PC:
Write PCL:
Read-Modify-Write:
Where PCH = program counter high byte (not an
addressable register), PCLATH = Program counter
high holding latch, dest = destination, WREG or f.
10.1.3
All bit manipulation instructions are done by first read-
ing the entire register, operating on the selected bit and
writing the result back (read-modify-write). The user
should keep this in mind when operating on special
function registers, such as ports.
DS30559A-page 74
Special Function Registers as
Source/Destination
STATUS AS DESTINATION
PCL AS SOURCE OR DESTINATION
BIT MANIPULATION
PCL
PCLATH
8-bit destination value
PCL
PCLATH
8-bit result
ALU operand
dest
PCH;
PCH;
PCL
PCL
1996 Microchip Technology Inc.