Mitsubishi DS5000TK, DS907x SIP manual ±20 Branch to the location PC+2 ±, Addressing

USER'S GUIDE

The 16±bit DPTR register may be used to access any Data Memory location within the 64K byte space.

MOVX @DPTR,A ; Load the Data Memory location

;pointed to by the contents of the

;DPTR register with the contents

;of the Accumulator.

Immediate Addressing

Immediate Addressing is used to access constants for use as operands which are contained in the current instruction in Program Memory.

ORL A, #040H ; Logical OR of the Accumulator ; with the constant value of 040H

Register±Indirect with Displacement Register±Indirect with Displacement Addressing is used to access data in look±up tables in Program Memory space. The location accessed is pointed to by the contents of either the DPTR or the PC registers, which are used as a base register added together with the contents of the Accumulator (A), which is used as an index register.

MOVC A, @DPTR+A ; Load the Accumulator with

;the contents of the Program

;Memory location pointed to

;by the value of the DPTR

;register plus the value

;contained in the Accumulator

Relative Addressing

Relative Addressing is used in the determination of a destination address for the Conditional Branch instruc- tions. Each of these instructions includes an 8±bit byte which contains a 2's complement address offset (±127

to +128) which is added to the PC to determine the des- tination address which will be branched to when the tested condition is found to be true. The PC points to the Program Memory location immediately after the Branch instruction when the offset is added. If the condition is found to be not true, then program execution continues from the address of the following instruction.

JZ	±20	; Branch to the location (PC+2) ±
20		; if the contents of the Accumulator
		; = 0

Page Addressing

Page Addressing is used by the Control Transfer instructions to specify a destination address within the 2K byte block in which the next contiguous instruction resides. The full 16±bit address is calculated by taking the highest-order five bits for the next contiguous instruction (PC+2) and concatenating them with the lowest-order 11±bit filed contained in the current instruction. 11±bit field provides an efficient instruction encoding of a destination address for these instructions.

0830 ACALL	100H ; Call to the subroutine at
	; address 0100H + current
	; page address

In this case the destination address would be 800H + 100H or 900H.

Extended Addressing

Extended Addressing is used in the Control Transfer Instructions to specify a 16±bit destination address within the entire 64K byte addressable range of the Secure Microcontroller.

LJMP 0FF80H ; Jump to address 0FF80H

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