Maxim Integrated DS4830 Optical Microcontroller - Manual (Page 197)

DS4830 User’s Guide
197
{L/S}DJNZ LC[n], src Decrement Counter, {Long/Short} Jump Not Zero
Description:
The DJNZ LC[n], src instruction performs a conditional branch based upon the associated Loop
Counter (LC[n]) register. The DJNZ LC[n], src instruction decrements the LC[n] loop counter and
branches to the address defined by src if the decremented counter has not reached 0000h.
Program branches can be relative or absolute depending upon the src specifier and may be
qualified by using the ‘L’ or ‘S’ prefixes as documented in the JUMP src opcode.
Status Flags: None
Operation:
LC[n]  LC[n] –1
LC[n] <> 0: IP  IP + src (relative) –or— src (absolute)
LC[n] = 0: IP  IP + 1
Encoding:
15 0
f10n 1101 ssss ssss
Example(s):
MOVE LC[1], #10h ; counter = 10h
Loop:
ADD
@DP[0]++ ; add data memory contents to Acc, post-inc DP[0]
DJNZ LC[1], Loop ; 16 times before falling through