z893232yfsc ZiLOG Semiconductor, z893232yfsc Datasheet - Page 39

• Manufacturer Part Number: z893232yfsc
• Description: 16-bit Digital Signal Processors
• Manufacturer: ZiLOG Semiconductor

RAM ADDRESSING
The address of the RAM is specified in one of three ways (Figure 22):
Register Indirect
Pn:b n = 0-2, b = 0-1
The most commonly used method is a register indirect
addressing method, where the RAM address is specified
by one of the three RAM address pointers (n) for each bank
(b). Each source/destination field in Figures 6 and 9 may
be used by an indirect instruction to specify a register
pointer and its modification after execution of the instruction.
DS95DSP0101 Q4/95
P2:0
P0:0
P1:0
RAM Pointers
%37
@@P1:0
@P1:0
%FF
%00
%37
Figure 31. RAM, ROM, and Pointer Architecture
256 x 16-Bit
%0321
RAM0
%1FFF
%0000
%0321
P R E L I M I N A R Y
Internal ROM
4K x 16-Bit
%1234
256 x 16-Bit
%0321
RAM1
@D0:1
D8
b
D0:0
D1:0
D2:0
D3:0
Figure 32. Indirect Register
D3
Each of the following instructions
load %1234 into the Accumulator:
%FF
%00
%04
D2
Data Pointers
LD A,@@P1:0
LD A,@D0:1
D1
n1
D0
RAM Pointers
n0
%0321
S4 / S3 = 01
16-B
RAM Pointer Register
Operation
RAM Bank
IT
D
IGITAL
D0:1
D1:1
D2:1
D3:1
P0:1
P1:1
P2:1
S
IGNAL
Z89323/373/393
P
ROCESSORS
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