15 February 1999
3112 Scott Blvd.
Santa Clara, CA 95054
+1 (408) 919-4111
FAX +1 (408) 919-4122
PROGRAMMABLE DIGITAL AUDIO PROCESSOR
Full-Function Digital Audio Processor Hardware
- 50 MIPS performance with multi-operation instructions
- Large internal RAMs/ROM plus low-cost external memory
- Wide selection of on-chip digital audio peripherals
- Flexible interface for host or no-host operation
Standard Software Functions in ROM
- Dolby Digital AC-3, 5.1 channel and 2 channel decoding
up to 640 Kbits per second
- Dolby Pro Logic encoding and decoding
- MPEG1 and MPEG2 two channel decoding with MPEG2
PES stream parsing, PTS decoding and SCR handling
- Tomorrow's ever-changing standards plus today's:
- Aureal A3D, Dolby Virtual Surround, Harman VMAx
- QSound QSurroundTM, Spatializer N-2-2TM, Home THX
- SRS TruSurround, Music Modes, Bass Management
- Serial and/or parallel data stream I/O
- Serial SPI, serial Z2C or 8-bit parallel host interface
- 3 serial input data ports and 4 serial data output ports
- Formatted S/PDIF receiver with up to 96 kHz sample rate
- Sample rates: 32 kHz, 44.1 kHz, 48 kHz or 96 kHz
- Formatted S/PDIF AC-3 and MPEG transmitter output
Low System Cost
- Host-less operation with no glue chips
- Separate internal PLLs for DSP core and audio I/O
- No external RAM required for 5.1 Dolby AC-3/MPEG2
- Wait-state generation for low-cost external memory
- 144-pin Plastic Thin Quad Flat Pack (TQFP) package
- 3.3 V supply with 5 V compatible I/O for low power
The Zoran ZR38650 is a full-function, high performance pro-
grammable digital audio signal processor. It is today capable of
real-time single-chip decoding of Dolby Digital AC-3 and
MPEG2 digital surround algorithms with its standard ROM and
SiliconSoftware functions. It is also today's best digital audio
platform for meeting tomorrow's constantly evolving digital audio
algorithm requirements. Using the proven ZR38000 architec-
ture, it is the fourth generation audio processor made by Zoran.
Because of its programmable high performance and high level of
integration, the ZR38650 is unusually flexible in meeting a wide
range of system requirements at the lowest possible system
cost. At the low end it can provide standard fixed decoding func-
tions with only a DAC and an optical interface for the S/PDIF
input in addition to the oscillator crystal. At the high end it can
provide eight channels of output, analog input, long-delay mem-
ories, custom operating features and the ability to be upgraded
SiliconSoftware product enhancements. Yet all
of this flexibility comes without design complexity. Highly config-
urable standard functions with a simple command structure
minimize software development, while a full set of development
tools are available for the highly-custom product developer.
The ZR38650 is suitable for primarily audio applications such as
Audio/Visual home theater receivers, Digital Audio Broadcast
(DAB), 3-D audio, six-channel speaker systems and Karaoke
processors; primarily video applications like SDTV and HDTV
stereo television receivers, digital cable and satellite TV set-top
boxes; and multimedia applications with both audio and video
like Multimedia PCs and the Digital Video Disk (DVD) players.
SPI or Z2C Serial Interface
General Purpose Control I/O
Figure 1. A Typical Low-Parts-Count ZR38650 System
The Zoran ZR38650 is the latest full-function digital audio pro-
cessing member of the ZR38000 digital signal processor
product line. It is especially configured with peripherals, I/O
capability and software for digital audio. Today, quality digital
audio starts with a primary decoding function and adds appropri-
ate data stream protocols and interfaces with I/O configurations
to match the application. The ZR38650 has these primary
decode and protocol software functions and yet has pro-
gram/data memory and processing cycles left for additional
product-distinguishing features. The ZR38650 also has the nec-
essary flexibility in system I/O and hardware configuration.
The ZR38650 is instruction-set compatible with the earlier
ZR38600, but has a higher 50-MIPS processing rate. This gives
the new faster 96-kHz sample rate S/PDIF decoding and
increased processing cycles for additional functions. Larger
internal program and data RAMs and ROM along with wide
external memories accommodate today's rapidly changing
needs for large complex algorithms. Other new hardware
features are a programmable timer, a Z2C serial host interface
and more support for the 24-bit I/O data formats.
AC-3 and MPEG with variations are the primary decoding func-
tions in use today. The ZR38650 has these and their associated
test function with the required set-up, operation and system
functions to make them usable in an end-user product. In addi-
tion, an ever increasing number of
SiliconSoftware functions can
add special enhancing and differentiating features to products.
Primary Decoding and Test Functions
The figure shows the simultaneous S/PDIF input and 5.1
channel DAC (Digital-to-Analog Converter) outputs of this
primary digital audio function, the six-channel AC-3 decoder.
Or with four channels of Pro Logic output in either of two DAC
forms: four channels directly or to an analog Pro Logic decoder.
PCM + Pro Logic
With two-channel PCM inputs the choice of functions is four-
channel Pro Logic decoding or two-channel stereo mixing,
including upmixing from only one input channel to two.
The MPEG1 decoder accepts either MPEG1 or MPEG2 input
streams and produces either Pro Logic DAC outputs or two-
channel stereo in DAC form.
A six-channel pink pseudo-random noise generator function is
included for user testing of speaker balance in their listening
space. Individual speakers can be enabled in any combination.
SiliconSoftware is a group of additional functions for the
ZR38650 provided by Zoran or third-party suppliers that can add
special features now or provide new functions in the future.
Currently there are six providers of 3-D audio which gives the
effect of a three-dimensional sound field with only two speakers.
These functions are Aureal A3D, Dolby Virtual Surround,
Harman VMAx, QSound QSurroundTM, Spatializer N-2-2TM and
Six- or Two-
Lt (Pro Logic)
Rt (Pro Logic)
Six- or Two-
One- or Two-
SRS TruSurround. They work with either two- or six-channel
inputs and the AC-3 or MPEG decoders.
Selected low-frequencies can be redirected to different
speakers with Bass Management. Useful with all types of
decoding to compensate for the types of speakers used.
DVD - Linear PCM
Special provisions are included for data formats and synchroni-
zation for AC-3/MPEG decoding with 3-D audio and bass
management for Digital Video Disk (DVD) applications.
Hall Effects/Music Modes
Adds the natural acoustical effects of a performance environ-
ment to the original recording environment.
Theater THX for use in consumer home entertainment systems.
Voice cancellation, pitch-shifting and echo and reverberation.
Custom Functions, Etc.
Product designers can always add custom functions and varia-
tions, often with very simple software additions.
Operation and Set-Up Functions
These control the simple start and stop operation of the
decoding functions and determine the initial hardware operation
These functions control the real-time operation including inter-
face transactions, program loading and in-circuit testing.
The ZR38650 is highly self-contained and can work with few
external parts as shown in Figure 1. However it is very flexible in
accommodating the needs of larger, higher performance
systems. Figure 2 shows all of the possible options that are sup-
ported to make a complete system.
The ZR38650 does not require a host microprocessor but if
there is one in the system it may be used to advantage. Either
the bit-serial SPI (Small Peripheral Interface) or Z2C interface,
or a byte-wide parallel interface may be used.
The encoded digital input data stream can use a bit-serial or
byte-parallel interface or S/PDIF receiver with the ZR38650
either a master or slave. Up to six-channels of analog signals
can be input in bit-serial ADC (Analog-to-Digital Converter)
formats in a master or slave mode.
Z2C or SPI Serial Interface
Figure 2. ZR38650 Composite System Block Diagram
RAM or ROM
Decoded audio outputs can be up to eight channels in bit-serial
DAC formats or six encoded channels from the S/PDIF
External memory is not normally needed but can be added for
program and/or digital audio data. Additional byte-wide program
storage gives different or additional functions when a host is not
used and allows a choice of ROM technologies to be employed
for future upgradability at minimum cost and parts count. Wider
32-bit program storage allows directly executing large functions
without downloading. External data memory may be required for
functions with long acoustical delays, input buffering or large
A more complete description of the ZR38650 software's opera-
tion and configurations and its hardware configurations follows.
Software - Operation
One of the major benefits of the ZR38650 is its ease of use for
the system developer under a broad range of system require-
ments. Standard functions are easy to use, yet custom features
can be added without falling back to custom software develop-
m e n t w i t h c o m p l i c a t e d r e a l - t i m e o p e r a t i n g s y s t e m
considerations or detailed I/O protocols. This follows from the
fact that all software functions are supplied with a common
command and response sequence for use with a host or an API
(Application Programming Interface) for calling from an internal
program. And each provides for adding custom functions in not
just one but a series of ways which depend upon the complexity
of the custom function.
This is shown schematically in Figure 3 where the operation,
set-up, primary, and
SiliconSoftware functions are shown in the
middle. Using the system utilities to maintain the communica-
tions with the host, the host can issue a sequence of commands
with responses to control the ZR38650's operation. The utilities
issue API calls to the functions. All of the software development
can be limited to the host microprocessor even when feature
types of variations in operation are based on getting information
back from the ZR38650's operation.
Alternatively, the control information in the commands can be
entered in a sequence of API calls issued from a custom
program running internally on the ZR38650 processor. Now no
host is required.
With either a host command/response stream or API calls,
custom functions in native ZR38001 code can be added without
losing the benefits of the ease of use in the common structure.
Table 1 is a summary of the commands and responses for the
standard primary, operation and set-up functions. Note there are
read and write commands to the ZR38650 and responses back
from the ZR38650 to the host. Responses are due to commands
during normal operations that are in progress or from certain
specific commands with read commands following.
Operate B, Etc.
Function C, Etc.
CFG Set-up, Etc.
ZR38650 Resident Control Program
Host Resident Control Program
Figure 3. ZR38650 Operation Control: Commands from a Host or Calls from a ZR38650 Resident Program
Table 1: Standard Function Command and Response Summary
Commands to ZR38650 to perform a specific function
Select AC-3 or AC-3 + Pro Logic decoder function
Select PCM or Pro Logic decoder functions with PCM input and mixer function
Select MPEG or MPEG + Pro Logic decoder function
Select pink noise generator function
Select user defined function
Resume selected function operation and unmute audio output
Mute audio output without stopping the selected operation
Restore muted audio output while continuing the selected operation
Stop operation, retain data in input buffer and mute audio output
Stop operation, flush the data in the input buffer and mute audio output
Return decoder status information using the READ command
Return the S/PDIF input channel status
Return the PTC and STC values for timing synchronization
Not a command, does not affect operation. Will return a Progress response.
Set the PLL programmable registers
Define the PLL configuration
Configure the ZR38650 I/O to the specific system hardware
Set the system time clock and video delay
Return 32-bit ROM version number using the READ command
Load and execute the N parameter words of bootstrap program
Write the S/PDIF output channel status
Define parameters for special functions
Interpret: load and execute four parameter words as a ZR38001 instruction
Set, test and return general purpose single-bit I/O registers
Load N 32-bit words to the core processor RAM at the given start address
Read N 32-bit words from core processor RAM at the given start address
Commands to ZR38650 to return Reply words to the host
Command to ZR38650 to return a Reply word after specific commands
Data words returned to the host as the result of sending specific commands followed by READ commands
Status and information about the AC-3 stream
Status and information about the PCM or Pro Logic stream
Status and information about the MPEG stream
Status and information about the PNG stream
Four byte version number of ROM read by VER command
Two words of GPIOC and GPIO registers
Two bits which indicate the PLL lock status
N 32-bit words from core processor RAM specified by PEEK command
S/PDIF input channel status
PTC and STC values of 32 bits each
Data words returned to host in the normal process of sending any command
Expected number of parameter words still to be received from host