Encoding:

Format:

BPOSGE32 offset

Purpose:

Branch on Greater Than or Equal To Value 32 inDSPControl Pos Field

Perform a PC-relative branch if the value of the pos field in the DSPControl register is greater than or equal to 32.

Description:

 if (DSPControlpos:6..0 >= 32) then goto PC+offset

First, the offset argument is left-shifted by two bits to form an 18-bit signed integer value. This value is added to the address of the instruction immediately following the branch to form a target branch address. Then, if the value of the pos field of the DSPControl register is greater than or equal to 32, the branch is taken and execution begins from the target address after the instruction in the branch delay slot has been executed.

Restrictions:

Pre-Release 6: Processor operation is UNPREDICTABLE if a control transfer instruction (CTI), specifically a branch, jump, NAL (Release 6), ERET, ERETNC (Release 5), DERET, WAIT, or PAUSE (Release 2) instruction is placed in the delay slot of a branch or jump.

Release 6: If a control transfer instruction (CTI) is executed in the delay slot of a branch or jump, Release 6 implementations are required to a signal a Reserved Instruction Exception.

Availability:

None.

Operation:

I:     se_offsetGPRLEN..0 = ( offset15 )GPRLEN-18 || offset15..0 || 02
      branch_condition = ( DSPControlpos:6..0 >= 32 ? 1 : 0 )
I+1:  if ( branch_condition = 1 ) then
          PCGPRLEN..0 = PCGPRLEN..0 + se_offsetGPRLEN..0
      endif

Exceptions:

Reserved Instruction, DSP Disabled

Programming Notes:

With the 18-bit signed instruction offset, the conditional branch range is ±128 Kbytes. Use jump (J) or jump register

(JR) instructions to branch to addresses outside of this range.