72V3644L10PF IDT, 72V3644L10PF Datasheet - Page 15

• Manufacturer Part Number: 72V3644L10PF
• Description: FIFO
• Manufacturer: IDT

Specifications of 72V3644L10PF

• Part # Aliases: IDT72V3644L10PF

BUS SIZING
9-bit byte format for data read from FIFO1 or written to FIFO2. The levels
applied to the Port B Bus Size select (SIZE) and the Bus-Match select (BM)
determine the Port B bus size. These levels should be static throughout FIFO
operation. Both bus size selections are implemented at the completion of Master
Reset, by the time the Full/Input Ready flag is set HIGH, as shown in Figure 2.
B when the bus size selection is either byte- or word-size. They are referred
to as Big-Endian (most significant byte first) and Little-Endian (least significant
byte first). The level applied to the Big-Endian select (BE) input during the LOW-
to-HIGH transition of MRS1 and MRS2 selects the endian method that will be
active during FIFO operation. BE is a don’t care input when the bus size
selected for Port B is long word. The endian method is implemented at the
completion of Master Reset, by the time the Full/Input Ready flag is set HIGH,
as shown in Figure 2.
on the IDT72V3624/72V3634/72V3644. Bus-matching operations are done
after data is read from the FIFO1 RAM and before data is written to the FIFO2
RAM. These bus-matching operations are not available when transferring
data via mailbox registers. Furthermore, both the word- and byte-size bus
selections limit the width of the data bus that can be used for mail register
operations. In this case, only those byte lanes belonging to the selected word-
or byte-size bus can carry mailbox data. The remaining data outputs will be
indeterminate. The remaining data inputs will be don’t care inputs. For
IDT72V3624/72V3634/72V3644 3.3V CMOS SyncBiFIFO
256 x 36 x 2, 512 x 36 x 2, 1,024 x 36 x 2
The Port B bus can be configured in a 36-bit long word, 18-bit word, or
Two different methods for sequencing data transfer are available for Port
Only 36-bit long word data is written to or read from the two FIFO memories
TM
WITH BUS-MATCHING
15
example, when a word-size bus is selected, then mailbox data can be
transmitted only between A0-A17 and B0-B17. When a byte-size bus is
selected, then mailbox data can be transmitted only between A0-A8 and B0-
B8. (See Figures 27 and 28).
BUS-MATCHING FIFO1 READS
word bus size is implemented, the entire long word immediately shifts to the
FIFO1 output register. If byte or word size is implemented on Port B, only the
first one or two bytes appear on the selected portion of the FIFO1 output register,
with the rest of the long word stored in auxiliary registers. In this case,
subsequent FIFO1 reads output the rest of the long word to the FIFO1 output
register in the order shown by Figure 2.
outputs are indeterminate.
BUS-MATCHING FIFO2 WRITES
to FIFO2 with a byte or word bus size stores the initial bytes or words in auxiliary
registers. The CLKB rising edge that writes the fourth byte or the second word
of long word to FIFO2 also stores the entire long word in the FIFO2 memory.
The bytes are arranged in the manner shown in Figure 2.
are don't care inputs.
Data is read from the FIFO1 RAM in 36-bit long word increments. If a long
When reading data from FIFO1 in byte or word format, the unused B0-B35
Data is written to the FIFO2 RAM in 36-bit long word increments. Data written
When writing data to FIFO2 in byte or word format, the unused B0-B35 inputs
COMMERCIAL TEMPERATURE RANGE