CY325 ETC, CY325 Datasheet - Page 27

• Manufacturer Part Number: CY325
• Description: Stepper System Controller
• Manufacturer: ETC

The 00 opcode specifies that one bit is to be operated on. The three least significant bits identify
the bit, while two other bits specify the bit group (user or data bus) and the operation (set or
clear). One argument bit is not used in single bit operations.
If the opcode is non-00, then all six bits are operated on as a group, with the relevant opcodes
shown below.
The actual application will constrain the number of User Selectable bits that are available. When
all features of the CY545 are used, only User Selectable bits 0 to 5 are available for general
purpose functions. If the CY233 is not used, or the parallel Hewlett Packard LED display is not
used, bits 6 and/or 7 will also be available. Finally, if the parallel command interface is not used,
and there is no local memory or HP LED display, the CY545 data bus lines will also be free, and
can be addressed as bits 8 to F of the Bit command. These special function lines can only be
tested or changed on an individual basis.
Since User Selectable bits 0 to 5 will always be available to the application, they can be
treated as a group, rather than as individual signals. The most significant two bits of the Bit
command parameter value indicate this selection. If any of these two bits is a 1, the lower 6 bits
of the value are treated as a group to modify USRB0 to USRB5 all at once. Options are to set all
six bits at once, as specified by the parameter value, to logical AND the parameter value with
the six bits, and to logical OR the parameter value with the six bits.
Two CY545 commands use the bits for special testing functions. They are:
© 2002 Cybernetic Micro Systems
T Bit,Addr
W Bit
NOTE: Setting or clearing these Special Function bits when
associated
interactions between the CY545 and the hardware. Also, the
CY545 will change the values on these signals as required for
normal support of the hardware. Be sure to manipulate only those
signals that are available to the application.
Bit Dependent Jump and Wait
Jump to address until bit matches value
Wait for bit to match value
hardware
is
present
22
could
cause
Chapter 6 - Bit Function Commands
unwanted
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