Z89175 Zilog., Z89175 Datasheet - Page 45

• Manufacturer Part Number: Z89175
• Description: Voice Processing Controllers
• Manufacturer: Zilog.

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
BUS
X
Y
A
SR
SP
PC
P
EXT0
EXT1
EXT2
EXT3
EXT4
EXT5
EXT6
EXT3-EXT0 (External Registers 3-0). These are the Mail-
box Registers used by the DSP and Z8 to 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)). This register
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 bit F and bit 9.
EXT5 (D/A and A/D Data Register). This register is used
by both D/A and A/D converters. The D/A converter is
loaded by writing to this register, while the A/D converter is
addressed by reading from this register. The Register
EXT5 is accessible only by the DSP.
DS97TAD0100
Register
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
Attribute
Table 11. DSP Registers
P R E L I M I N A R Y
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
and D/A converters, and the mailbox and interrupt interfac-
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 11.
EXT6 (Analog Control Register). This register controls the
D/A and A/D converters. It is a read/write register accessi-
ble only by the DSP.
DSP Z8 Mail Box
To receive information from the DSP, the Z8 uses eight in-
coming registers which are mapped in the Z8 extended
Register File (Bank B, 08 to 0F). The DSP treats these as
four 16-bit registers that correspond to the eight incoming
Z8 registers (Figure 32).
Register Definition
Voice Processing Controllers
Z89175/Z89176
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