Computer Hardware User's Guide

LDP Load Data-Page Pointer
13-134
Syntax LDP src, DP
Operation src → data-page pointer
Operands src is the 8 MSBs of the absolute 24-bit source address ( src ).
The “DP” in the operand is optional.
Opcode
31 2423 16 8 7 015
000 01 0
0 00
1
1 1
0000
00000000 src
Description This pseudo-op is an alternate form of the LDUI instruction, except that LDP
is always in the immediate addressing mode. The src operand field contains
the eight MSBs of the absolute 24-bit src address (essentially, only
bits 23–16 of
src are used). These eight bits are loaded into the eight LSBs
of the data-page pointer.
The eight LSBs of the pointer are used in direct addressing as a pointer to the
page of data being addressed. There is a total of 256 pages, each page 64K
words long. Bits 31–8 of the pointer are reserved and should be kept set to 0.
Cycles 1
Status Bits LUF Unaffected
LV Unaffected
UF Unaffected
N Unaffected
Z Unaffected
V Unaffected
C Unaffected
OVM Operation is not affected by OVM bit value.
Example LDP @809900h, DP
or
LDP @809900h
Before Instruction After Instruction
DP 065 DP 080
LUF 0 LUF 0
LV 0 LV 0
UF 0 UF 0
N 0 N 0
Z 0 Z 0
V 0 V 0
C 0 C 0
Mode Bit