请您解释一下altera lpm_fifo_dc0中 wrusedw和rdusedw信号的含义

Jermaine618

请您解释一下altera lpm_fifo_dc0中 wrusedw和rdusedw信号的含义！

stone_1979

SAME QUESTIOIN

kaku817

回复 1# Jermaine618

# FIFO:  write-port -> (data-in) -> [buffer] -> (data-out) -> read-port

# lpm_fifo_dc: it is dual-clock FIFO, that is, one clock input for read-port,
and another clock input for write-port.

# wrusedw: it shows total used word in FIFO from view point of write-port

# rdusedw: it shows total used word in FIFO from view point of read-port

# So, why it needs two separated "used word" indications for write-port and read-port?
(ANS)
Because there are two seperated clock inputs for write-port and read-port.
These clocks may not be the same (this is the key feature of dual-clock FIFO)
So wrusedw is sync with clock of write-port, rdusedw is sync with clock of read-port.

how1e

kaku817 发表于 2011-2-23 23:24
回复 1# Jermaine618

# FIFO:  write-port -> (data-in) ->  -> (data-out) -> read-port

thanks!!!