Encoding:

RR

11101

rx

nd

1

l

0

ra

0

J(AL)R(C)

00000

5

3

1

1

1

5

Format:

JRC rx

MIPS16e

Jump Register Through MIPS16e GPR, Compact

Purpose:

To execute a branch to an instruction address in a register

Description:

PC = GPR[rx]

The program unconditionally jumps to the address specifiein GPR rx, with no delay slot instruction. The instruction sets the ISA Mode bit to the value in GPR rx bit 0.

Bit 0 of the target address is always zero so that no Address Exceptions occur when bit 0 of the source register is one.

The opcode and function fieldescribe a generaljump-thru-register operation, with the nd (no delay slot),l (link), and ra (source register is ra) fieldas variables. The individual instructions, JALR, JR, JALRC, and JRC have specifi values for these variables.

Restrictions:

The effective target address in GPR rx must be naturally-aligned. If bit 0 is zero and bit 1 is one,then an Address

Error exception occurs when the jump target is subsequently fetched as an instruction.

Operation:

I: PC = GPR[Xlat(rx)]GPRLEN-1..1 || 0
   ISAMode = GPR[Xlat(rx)]0

Exceptions:

None.

Programming Notes:

Unlike most MIPS "jump" instructions, JRC does not have a delay slot.