SCAS200B - JANUARY 1991 - REVISED JULY 1995
The SN74ACT7807 is a 2048-word by 9-bit FIFO with high speed and fast access times. It processes data at rates up to 67 MHz and access times of 12 ns in a bit-parallel format. Data outputs are noninverting with respect to the data inputs. Expansion is easily accomplished in both word width and word depth.
The write-clock (WRTCLK) and read-clock (RDCLK) inputs should be free running and can be asynchronous or coincident. Data is written to memory on the rising edge of WRTCLK when the write-enable (WRTEN1/DP9, WRTEN2) inputs are high and the input-ready (IR) flag output is high. Data is read from memory on the rising edge of RDCLK when the read-enable (RDEN1, RDEN2) and output-enable (OE) inputs are high and the output-ready (OR) flag output is high. The first word written to memory is clocked through to the output buffer regardless of the levels on RDEN1, RDEN2, and OE. The OR flag indicates that valid data is present on the output buffer.
The FIFO can be reset asynchronous to WRTCLK and RDCLK.
must be asserted while at least
four WRTCLK and four RDCLK cycles occur to clear the synchronizing
registers. Resetting the FIFO initializes the IR, OR, and HF flags
low and the AF/AE flag high. The FIFO must be reset upon power up.
The SN74ACT7807 is characterized for operation from 0°C to 70°C.