CY545 Stepper System Controller
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When a serial display is selected, the next bit, MB1, selects between a standard serial output,
used for connections to a host computer serial port or general terminal serial port, or a
specialized LCD display device, controlled by the CY325 LCD Display Controller.
When bit MB1 is zero, a standard serial display is used, and the CY545 does not perform any
special formatting of the output. This is the power-on default option.
When MB1 is one, the CY325 based display is used, and the CY545 adds special formatting
strings to the data, putting the query results in fixed places on the display screen. This mode
should not be used without a CY325 controller. For more information about this device, contact
Cybernetic Micro Systems or visit our web site at www.controlchips.com.
When a parallel display is selected by MB0, MB2 selects between a standard parallel output,
and a special Hewlett Packard LED display.
When MB2 is zero, the standard parallel output is selected. This uses the IO_REQUEST and
BUSY signals to control the reading of information from the CY545. Also, the CY545 will drive
the FPL signal low (shared function with USRB6) when it has something to output. This protocol
will work with a standard two-line handshake or with the parallel functions of a CY233 Network
controller.
When MB2 is one, the special HP LED display is selected. In this case, all output from the
CY545 goes to the local HP LED display, and a special signal, HP_SEL (shared function with
USRB7), is generated while the CY545 is writing to the display. More information about support
for this display is provided in a later section.
When a Mode command is issued with MB5 set to one, the CY545A enables the CTS/ function
on the USRB6 (the CTS function is not available on older parts prior to the CY545A). After any
reset, this function is disabled, and USRB6 is high, so the CTS/ signal is off. A Mode command
must be issued to the CY545 before the CTS/ function is enabled.
When the signal is low, the CY545 is ready for more serial characters, and when the signal is
high, the CY545 is busy processing a command. The CTS/ signal can be used to automatically
control the rate of serial communications from the host system, stopping transmissions while the
signal is at TTL one. This allows the host to send a sequence of commands, including motion
commands that may take some time to execute, without worrying about the CY545 being able to
accept the commands. The hardware control insures that the CY545 will always indicate when it
is ready for more serial data. The exception to this is during use of the external jog line, in which
CTS is not set busy during Jog stepping.
Since the CTS/ signal is initially disabled, the CY545 must receive a Mode command that
enables the signal before it can be used by the host. There are three alternatives for turning on
the CTS/ function.
© 2002 Cybernetic Micro Systems
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Chapter 9 - Operating Mode Command
ETC [ ETC ]
