
STD130
5-148
Samsung ASIC
FIFO_HD
High-Density Synchronous First-In First-Out Memory
Pin Descriptions
Name
I/O
Description
RCK
Read Clock
Read Clock input. Upon the rising edge of RCK, it begins a read
operation when REN is low, RST is high, RTM is high and EF is low.
Read Enable input. When REN is low, the read access occurs properly.
Conversely when REN is high, no read access can occur and the read
port of the FIFO_HD goes to power down mode.
REN is latched at the rising edge of RCK.
Output Enable input. The data output enable is asynchronously
operated regardless of the state of other inputs. When OEN is high,
DOUT is disabled and goes to high-impedance state.
Reset input. Upon the falling edge of RST, the reset mode is initiated.
RST resets the read and write pointer to their initial position. RST sets
EF and resets FF. RST makes DOUT[] zero.
Retransmit input. Upon the falling edge of RTM, the retransmit mode is
initiated, provided that RST is high. RTM resets the read pointer to its
initial position. RTM makes DOUT[] zero.
Write Clock input. Upon the rising edge of WCK, it begins a write
operation when WE is low, RST is high and FF is low.
Write Enable input. When WEN is low, a write access occurs properly.
Conversely when WEN is high, no write access can occur and the write
port of the FIFO_HD goes to power down mode. WEN is latched at the
rising edge of WCK.
Data input bus. DI[] is latched on the rising edge of WCK. Data input is
written into the addressed location in write mode.
Empty Flag. If the memory has no data to be read, EF goes high. Valid
reset makes EF high and valid retransmit makes it low.
Full Flag. If the memory has no vacancy to write data, FF goes high.
Valid reset makes FF low.
Data output bus. Data output is valid after the rising edge of RCK while
the FIFO_HD is in read mode when OEN is low. Conversely when OEN
is high, DOUT[] goes to high-impedance state. By reset or retransmit
operation. DOUT[] goes to 0.
REN
Read Enable
OEN
Data Output
Enable
RST
Reset
RTM
Retransmit
WCK
Write Clock
WEN
Write Enable
DI
Data In
EF
Empty Flag
FF
Full Flag
DOUT
Data Output