Z8932120PSC Datasheet, PDF (29/40 Pages) Zilog, Inc. – 16-BIT DIGITAL SIGNAL PROCESSORS

Zilog
Z89321/371/391
16-Bit Digital Signal Processors
A/D Accommodation
High-Speed Serial Port
The CODEC interface can be used for serial A/D or serial The Z89321 CODEC interface can be used as a high-
1 ^{D/A transmission. The interface provides the necessary speed serial port. The necessary control signals are pro-}
control signals to adapt to many standard serial convert- vided for adaptation to standard processors or external pe-
ers. The low-pass and smoothing filters are necessary for ripherals. Byte, word, or 64-bit data can be transmitted at
systems with converters.
speeds up to 10 Mbps. (Condition includes a 20 MHz os-
cillator. Data can be transferred with single-cycle instruc-
tions to an internal register file.)
Z89321/371/391
SCLK
FSO
FS1
RXD
TXD
Serial A/D
CLKIN
Communicate
Data
Serial
Data Out
Serial A/D
CLKIN
Serial
Data In
Communicate
Data
Low-Pass
Filter
Smoothing
Filter
Figure 26. A/D, D/A Implementation Block Diagram
Analog
In
Analog
Out
Table 7. Tabulated Transmission Rates*
Transmission
Rate
Maximum SCLK
10 Mbps
Maximum Frame Sync
8-bit
769.2 kHz
16-bit
476.2 kHz
Stereo (64-bit)
263.2 kHz
Note: Calculations consider the interrupt access time (typically
four cycles), transfer of data, loading of new data, and latency pe-
riods between CODEC transfers. During the interrupt cycle, de-
velopers often execute additional software, affecting the
maximum transfer rate. Calculations are for single-channel trans-
fers only.
8-Bit CODEC Interface
The Z89321 provides an option for a standard 8-bit CO-
DEC interface. Hardware m-law compression is available
(expansion performed by software lookup table). The CO-
DEC interface transmits data consisting of 8-bit or com-
pounded 8-bit information. Figure 27 shows a typical sche-
matic arrangement.
The timing for this type of arrangement is presented in Fig-
ure 28. The flexible design provides adaptation for 16-bit
linear CODEC.
DS97DSP0100
PRELIMINARY
29