em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 24

• Manufacturer Part Number: em78f644nso28s
• Description: Flash Series 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

EM78F648/644/642/641/548/544/542/541N
8-Bit Microcontroller
14 •
"ADD R2, A" allows a relative address to be added to the current PC, and the
ninth and above bits of the PC will increase progressively.
"MOV R2, A" allows loading an address from the "A" register to the lower 8 bits of
the PC, and the ninth and tenth bits of the PC remain unchanged.
Any instruction except “ADD R2, A” that is written to R2 (e.g., "MOV R2, A", "BC
R2, 6") will cause the ninth bit and the tenth bit (A8~A9) of the PC to remain
unchanged.
All instructions are single instruction cycle (fclk/2, fclk/4, fclk/8 or fclk/16) except
for instructions that would change the contents of R2 and “LCALL”, “LJMP”,
“TBRD” instructions. The “LCALL”, “LJMP” and “TBRD” instructions need two
instructions cycle.
Figure 6-1 Program Counter Organization
(This specification is subject to change without further notice)
Product Specification (V1.0) 05.05.2010