z89136 ZiLOG Semiconductor, z89136 Datasheet - Page 43

• Manufacturer Part Number: z89136
• Description: Low-cost Dtad Controller
• Manufacturer: ZiLOG Semiconductor

Zilog
DSP REGISTERS DESCRIPTION
General. The DSP is a high-performance second genera-
tion CMOS Digital Signal Processor with a modified Har-
vard-type architecture with separate program and data
ports. The design has been optimized for processing pow-
er and saving silicon space.
Registers. The DSP has eight internal registers and sev-
en external registers. The external registers are for the A/D
and D/A converters, and the mailbox and interrupt interfac-
Register
BUS
X
Y
A
SR
SP
PC
P
EXT0
EXT1
EXT2
EXT3
EXT4
EXT5
EXT6
EXT3-EXT0. (External Registers 3-0) are the MailBox
Registers in which the DSP and the Z8 communicate.
These four 16 bit registers correspond to the eight outgo-
ing and eight incoming 8-bit registers in Bank B of the Z8’s
Expanded Register File.
EXT4. (DSP Interrupt Control Register (ICR)) controls the
interrupts in the DSP as well as the interrupts in common
between the DSP and the Z8. It is accessible by the DSP
only, except for the bit F and bit 9.
DS97TAD0300
Attribute
Read
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read/Write
Read
Read
Write
Read
Write
Read
Write
Read
Write
Read/Write
Read
Write
Read/Write
Table 9. DSP Registers
P R E L I M I N A R Y
Register Definition
Data-Bus
X Multiplier Input, 16-Bit
Y Multiplier Input, 16-Bit
Accumulator, 24-Bit
Status Register
Stack Pointer
Program Counter
Output of MAC, 24-Bit
Z8 ERF Bank B, Register 00-01 (from Z8)
Z8 ERF Bank B, Register 08-09 (to Z8)
Z8 ERF Bank B, Register 02-03 (from Z8)
Z8 ERF Bank B, Register 0A-0B (to Z8)
Z8 ERF Bank B, Register 04-05 (from Z8)
Z8 ERF Bank B, Register 0C-0D (to Z8)
Z8 ERF Bank B, Register 06-07 (from Z8)
Z8 ERF Bank B, Register 0E-0F (to Z8)
DSP Interrupt Control Register
A/D Converter
D/A Converter
Analog Control Register
ing between DSP to the Z8. External registers are access-
ed in one machine cycle, the same as internal registers.
DSP Registers
There are 15 internal and extended 16-bit registers which
are defined in Table 9.
EXT5. (D/A and A/D Data Register) is used by both D/A
and A/D converters. The D/A converter will be loaded by
writing to this register, while the A/D converter will be ad-
dressed by reading from this register. The Register EXT5
is accessible by the DSP only.
EXT6. (Analog Control Register) controls the D/A and A/D
converters. It is a read/write register accessible by the
DSP only.
Low-Cost DTAD Controller
Z89135/136 (ROMless)
1-43
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