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User Manual
Appendix B
GFK-1742F
Jan 2020
DSM314 Communications Request Instructions
400
Status Word Pointer Offset (Word 4): This word contains the offset within the memory type
selected. Note: The Status Word Pointer Offset is a zero-based number. In practical terms,
this means that you should subtract one from the address number that you wish to specify.
For example, to select %R0001, enter a zero (1
–
1 = 0). Or, if you want to specify %R0100,
enter a 99 (100
–
1 = 99). Note that the memory type, %R in this example, is specified by the
previous word (see the “Status Word Pointer Memory Type” explanation above).
Idle Timeout Value (Word 5): Since the DSM always uses the NOWAIT mode (WAIT/NOWAIT
flag always set to zero), this Idle Timeout Value parameter is not used for the DSM. Set it to
zero.
Maximum Communication Time (Word 6): Since the DSM always uses the NOWAIT mode
(WAIT/NOWAIT flag always set to zero), this Maximum Communication Time parameter is
not used for the DSM. Set it to zero.
Command Code (Word 7): Use one of the eight Command Codes from the table below. The
Command Codes are given as hexadecimal numbers.
Table 86: UDT COMM REQ Command Codes
User Data Table (UDT) COMM REQ Commands
Command Code
Command Description
D001h
Write to UDT Segment 1
D101h
Write to UDT Segment 2
D201h
Write to UDT Segment 3
D301h
Write to UDT Segment 4
D804h
Read from UDT Segment 1
D904h
Read from UDT Segment 2
DA04h
Read from UDT Segment 3
DB04h
Read from UDT Segment 4
UDT Segment Data Size (Word 8): Specifies the memory size, in bytes, of the UTP Segment
to be accessed. This value should always be 2048 bytes (800h for hexadecimal).
Data Memory Type (Word 9): This word specifies the memory type that will be used for host
controller data. Each memory type has a unique code number, shown in the Memory Type
Codes table below. So, for example, to specify %R memory, you would put either the
decimal code number 8 or the hexadecimal code number 08h in this word.
Note:
The UDT COMM REQ does not support discrete memory (%I or %Q) for the Data Memory Type.