CY545 Stepper System Controller
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However, there is a crystal frequency of 14.7456 MHz at which the CY545 can be operated in
the adaptive mode. With this frequency, the internal resolution of the CY545 baud rate timer
allows it to adapt to all standard baud rates from 300 to 19,200 baud, plus two higher, non-
standard rates of 38,400 and 76,800 baud.
Also, the CY545 serial interface works on a fixed format character, which is always 8 data bits,
with no parity bit, and one stop bit. All 8 data bits are used to interpret the command character
values, so be sure to send the proper 8 bit codes for the various ASCII command characters.
Finally, the CY545 optionally implements a Clear to Send signal ("CTS/") which may be used by
the host system to indicate when the CY545 is busy processing a command. No additional
characters should be sent to the CY545 while CTS/ is off (TTL high). Once the CY545 has
finished processing the current command, CTS/ will be enabled again, indicating that the CY545
is ready for more serial characters. The polarity of the CY545 CTS/ signal allows it to be
connected directly to your host system CTS RS-232 signal, through a standard RS-232 line
driver. No additional logic is required.
The CTS/ signal shares functions with User Bit 6, which is also the CY233 FPL/ signal. Since
the signal has multiple functions, the CTS/ function is disabled at power on or any restart
operation. You must issue a Mode command with MBit 5 set in order to enable the CTS/ signal.
See the later section on the Mode Command for more details.
© 2002 Cybernetic Micro Systems
14
Chapter 3 - Command Interfaces
ETC [ ETC ]
