
Axcelerator Family FPGAs
2- 84
v2.8
Table 2-96 FIFO Signal Description
Signal
Direction
Description
WCLK
Input
Write clock (active either edge).
FWEN
Input
FIFO write enable. When this signal is asserted, the WD bus data is latched into the
FIFO, and the internal write counters are incremented.
WD[N-1:0]
Input
Write data bus. The value N is dependent on the RAM configuration and can be 1,
2, 4, 9, 18, or 36.
FULL
Output
Active high signal indicating that the FIFO is FULL. When this signal is set,
additional write requests are ignored.
AFULL
Output
Active high signal indicating that the FIFO is AFULL.
AFVAL
Input
8-bit input defining the AFULL value of the FIFO.
RCLK
Input
Read clock (active either edge).
FREN
Input
FIFO read enable.
RD[N-1:0]
Output
Read data bus. The value N is dependent on the RAM configuration and can be 1,
2, 4, 9, 18, or 36.
EMPTY
Output
Empty flag indicating that the FIFO is EMPTY. When this signal is asserted,
attempts to read the FIFO will be ignored.
AEMPTY
Output
Active high signal indicating that the FIFO is AEMPTY.
AEVAL
Input
8-bit input defining the almost-empty value of the FIFO.
PIPE
Input
Sets the pipe option on or off.
CLR
Input
Active high clear input.
DEPTH
Input
Determines the depth of the FIFO and the number of FIFOs to be cascaded.
WIDTH
Input
Determines the width of the dataword / width of the FIFO, and the number of the
FIFOs to be cascaded.