PCL6045B Datasheet, PDF (32/176 Pages) List of Unclassifed Manufacturers – User Manual For PCL6045B Pulse Control LSI

7-4. Register control command
By writing a Register Control command to COMB0 (Address 0 when a Z80 I/F is used), the LSI can copy
data between a register and the I/O buffer.
When using the I/O buffer while responding to an interrupt, a precaution is required, reading the I/O buffer
contents before using it and returning it to its original value after use.
7-4-1. Procedure for writing data to a register (the axis assignment is omitted)
1) Write the data that will be written to a register into the I/O buffer (addresses 4 to 7 when a Z80 I/F is
used). The order in which the data is written does not matter. However, secure two reference clock
cycles between these writings.
2) Then, write a "register write command" to COMB0 (address 0 when a Z80 I/F is used).
After writing one set of data, wait at least two cycles (approx. 0.1 µsec when CLK = 19.6608 MHz)
before writing the next set of data. In both case1) and case 2), when the WRQ output is connected
to the CPU, the CPU wait control function will provide the waiting time between write operations
automatically.
A0 to A2
CS
4h
5h
6h
7h
0h
Next address
WR
D0 to D7
Command Data
Data
Data Command
Command
Two reference
clock cycles or more
Four reference
clock cycles
or more
7-4-2. Procedure for reading data from a register (the axis assignment is omitted)
1) First, write a "register read out command" to COMB0 (address 0 when a Z80 I/F is used).
2) Wait at least four reference clock cycles (approx. 0.2 µsec when CLK = 19.6608 MHz) for the data to be
copied to the I/O buffer.
3) Read the data from the I/O buffer (addresses 4 to 7 when a Z80 I/F is used). The order for reading data
from the I/O buffer does not matter. There is no minimum time between read operations.
When the output is connected to the CPU, the CPU wait control function will provide the waiting time
between write operations automatically.
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