Motorola DSP96002 - Manual (Page 270)

A - 82 DSP96002 USER’S MANUAL MOTOROLA
ENDDO End Current DO Loop ENDDO
00 0000 0000 0111
31 14 13 0
0000 0000 0000 0000 00
Operation:
SSL(LF)
→
SR; SP-1
→
SP
SSH
→
LA; SSL
→
LC; SP-1
→
SP
Assembler Syntax:
ENDDO
Description:
This instruction will cause the termination of the current hardware DO loop before the current loop counter
(LC) equals one. If the value of the current DO loop counter is needed, it must be read before the execution
of the ENDDO instruction. Initially, the loop flag (LF) is restored from the system stack and the remaining
portion of the status register (SR) and the program counter (PC) are purged from the system stack. The
loop address (LA) and the loop counter (LC) registers are them restored from the system stack.
Restrictions:
Due to pipelining, and the fact that the ENDDO instruction accesses the program controller registers, the
ENDDO instruction must not be immediately preceded by any of the following instructions:
Immediately before ENDDO MOVEC to LA, LC, SR, SSH, SSL, OR SP
MOVEM to LA, LC, SR, SSH, SSL, OR SP
MOVEP to LA, LC, SR, SSH, SSL, OR SP
MOVEC from SSH
MOVEM from SSH
MOVEP from SSH
ORI MR
ANDI MR
Also, the ENDDO instruction cannot be the next to last instruction in a DO loop (at LA-1).
CCR Condition Codes: Not affected.
ER Status Bits: Not affected.
IER Flags: Not affected.
Instruction Fields:
Instruction Format: ENDDO
None
Timing: 2 oscillator clock cycles
Memory: 1 program words