hi-6131pqtf QuickLogic Corp, hi-6131pqtf Datasheet - Page 226

• Manufacturer Part Number: hi-6131pqtf
• Description: Mil-std-1553 / Mil-std-1760 3.3v Bc / Mt / Rt Multi-terminal Device
• Manufacturer: QuickLogic Corp

This command can be used to read just the current RT1
or RT2 Control Word, or may be used to start a multi-
word read because memory pointer auto-increment oc-
curs after the Control Word is read.
Six single-byte SPI commands add an offset to the cur-
rent address pointer value, then read the addressed
memory location; the read value is then written to the
address pointer register 15. The new pointer value is
used to start a read or write operation:
Primary use occurs when an RT1 or RT2 Descriptor
Table Control Word was just read. For example, the last
Command Read Operation
Command Read Operation
Command Write Operation
0xE8
0xF0
0xF8
0x48
0x50
0x68
0x70
0x78
Copy RT1 Current Control Word
Address register 3 into the enabled
Memory Address Pointer. Read the
location addressed by the new pointer
value.
Copy RT2 Current Control Word
Address register 5 into the enabled
Memory Address Pointer. Read the
location addressed by the new pointer
value.
Read the location addressed by the
enabled Memory Address Pointer. Write
the value just read into the Memory
Address Pointer. Then read.
Add 1 to the enabled Memory Address
Pointer. Read value at newly addressed
loca-tion and write it into the Memory
Address Pointer. Then read.
Add 2 to the enabled Memory Address
Pointer. Read value at newly addressed
loca-tion and write it into the Memory
Address Pointer. Then read.
Read the location addressed by the
enabled Memory Address Pointer. Write
the value just read into the Memory
Address Pointer. Then write.
Add 1 to the enabled Memory Address
Pointer. Read value at newly addressed
loca-tion and write it into the Memory
Address Pointer. Then write.
Add 2 to the enabled Memory Address
Pointer. Read value at newly addressed
loca-tion and write it into the Memory
Address Pointer. Then write.
HOLT INTEGRATED CIRCUITS
HI-6130, HI-6131
226
op code performed was 0x48, reading the RT1 Control
Word for the last command. After reading the Control
Word, the enabled Memory Address Pointer automati-
cally incremented. The host can examine flag bits con-
tained in the just-read Control Word to determine the
applicable data buffer (e.g., Data Buffer A, Data Buffer B
or the Broadcast Data Buffer) then directly service that
buffer using these op codes; the three data buffer point-
ers occur in the three words following the initially read
Control Word.
These six commands can be used to read or write a
single location, or may be used to start a multi-word read
or write that uses the pointer’s auto-increment feature.
When some or all subaddress or mode commands are
not programmed to trigger host interrupts, a different
single-byte SPI command may be useful if polling the
RT1 or RT2 Descriptor Table for message activity. In this
situation, the host may poll a series of Descriptor Table
Control Words looking for instances where the DBAC
activity bit is set. The DBAC (Descriptor Block Accessed)
flag is set in the Control Word each time the correspond-
ing command is completed. The process of reading the
Control Word automatically resets the register’s DBAC
bit so the host can detect activity the next time the DBAC
flag is set by the device.
Since RT1 or RT2 Descriptor Table Control Words are
spaced four words apart, this command is useful when
polling a series of descriptor table Control Words:
Primary use occurs when the address pointer initially
points to the first Descriptor Table Control Word in a se-
ries of Control Words to be polled (every fourth word).
After 8 SCK clocks for the SPI command, each instance
of this command reads a single location using 16 SCK
clocks. If CS remains low after 24 clocks and SCK con-
tinues, a multi-word read begins, using the address
pointer’s auto-increment feature. The second word read
is at (Control Word address + 4), the next Control Word
in the table.
Another single-byte SPI command is useful when ser-
vicing interrupts. When enabled interrupts occur, two
words are written to the circular 64-word Interrupt Log
Buffer, and the Interrupt Log Address register 0x000A
is updated to show the storage address where interrupt
information words will be stored for the next occurring
interrupt. Buffer starting address is 0x0180 and ending
address is 0x01BF. Because two words are written to
Command Read Operation
0x60
read addressed location then add 4 to
pointer