ST75C520PQFP View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'ST75C520PQFP' PDF : 45 Pages View PDF
ST75C520
V.2 - Command Set
The Command Set has the following attractive
features :
- user friendly with easy to remember mnemonics,
- possibility of straightforward expansion with new
commands to suit specific customer require-
ments,
- easy upgrade of existing software using previous
modem based SGS-THOMSON products.
The command set has been designed to provide
the necessary functional control on the ST75C520.
Each command is classified according to its syntax
and the presence/absence of parameters. In the
case of a parametric command, parameters must
first be written into the dual port RAM before the
command is issued. Acknowledge and error report
is issued for each command entered.
V.2.1 - Command Set Summary
V.2.1.1 - Operational Control Commands
INIT Initialize. Initialize the modem engine.
Set all parameters to their default values
and wait for commands of the control
processor. Non parametric command.
IDT
Identify. Return the product identification
code. Non parametric command.
SLEEP Turn to low power mode, the ST75C520
enters the low power mode and stops its
crystal oscillator to reduce power
consumption. In this mode all the clocks
are stopped and the dual RAM is
unreachable.
HSHK Handshake. Begins the handshake
sequence. The modem engine
generates all the sequences defined in
the ITU-T recommendations. A status
report indicates to the control processor
the state of the handshake. This
command only applies to modes where
a handshake sequence is defined. A
CONF command must have been issued
prior to the use of HSHK. Non parametric
command.
STOP FAX S to p. Stop FAX Half-dup le x
transmitter. Non parametric command.
SYNC
FAX Synchronize. Start/Stop of FAX
Half-duplex receiver. Parametric
command.
CSE Clear Status Error. Selectively clears the
Error status byte SYSERR. Parametric
command.
SETGN Set Gain. This command sets the global
gain factor, which is used for the transmit
samples. Parametric command.
V.2.1.2 - Data Communication Commands
XMIT Tra n smit Da t a. S t art / st o p t he
transmission of data in parallel mode.
After a XMIT command, the ST75C520
sends the data contained in its dual port
RAM.
SERIAL Select Serial or Parallel Mode. This
command selects the data source, i.e.
either parallel or serial. The parallel
mode uses a part of the dual port RAM
as a double buffer. The serial mode uses
the serial synchronous I/O. Parametric
command.
FORM Selects the Transmission Format (only in
parallel mode). This command
configures the data interface for both
receiver and transmitter according to the
selected data format. Parametric
command (HDLC or synchronous). In
serial mode, format is always
synchronous.
V.2.1.3 - Memory Handling Commands
MW
Memory Write. This command is used to
write an arbitrary 16-bit value into the
writable memory location currently
specified by a parameter. Parametric
command.
MR
Memory Read. This command allows the
controller to read any of the ERAM or
CROM (ST75C520 memory spaces)
location without interrupting the
processor. Parametric command.
CR
Complex Read. This command allows
the controller to read at the same time
the real and imaginary part of a complex
value stored in a double ERAM or
CROM location. This feature is very
interesting for eye pattern software
control and for equalization monitoring.
This command insures that the real and
imaginary parts are sampled in the
memory at the same time (integrity).
Parametric command.
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