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STD130
5-126
Samsung ASIC
ARFRAM_HD
High-Density Multi-Port Asynchronous Register File
Logic Symbol
Function Description
ARFRAM_HD is a multi-port asynchronous register file which is provided as a compiler. ARFRAM_HD is
intended for use in high-density applications. It allows maximum 4 ports with configurable 1-to-2 read ports
and 1-to-2 write ports. All read and write ports are fully independent. On the rising edge of CK, the write
cycle is initiated when WEN is low. While CK is high, the data at DI[] is written into the memory location
specified on WA[]. At the falling edge of CK, the write cycle is terminated. If WEN is high, WA[] and DI[] are
disabled . It is called “write standby mode”. When REN and OEN are low, the data stored in the memory
location specified on RA[] becomes valid through DOUT[] after a delay. If REN is high, RA[] is disabled and
DOUT[] remains in the previous data output. It is called “read standby mode”. When OEN is high, DOUT[] is
placed in a high-impedance state regardless of REN.
ARFRAM_HD Function Table
CK
X
↑
↓
X
X
X
X
WEN
H
L
L
X
X
X
X
WA
X
Valid
X
X
X
X
X
DI
X
RA
X
X
X
X
X
REN
X
X
X
X
H
L
↓
OEN
X
X
X
H
L
L
L
DOUT
X
X
X
Z
DOUT(t-1)
MEM(RA)
MEM(RA)
Comment
Write standby mode
Write cycle starts
Write cycle ends
Unconditional tri-state output
Read standby mode
Read cycle
Read cycle with REN-controlled
Valid
X
X
X
X
X
Toggle
Valid
Features
High-density application
Suitable for high-speed application
Synchronous write operation
Asynchronous read operation
Fully independent port
Latched input and output
Separated data I/O
Flexible aspect ratio
Asynchronous tristate output
Zero standby current
Configurable 1-to-2 read ports
Configurable 1-to-2 write ports
Up to 16K bits capacity
Up to 1024K number of words
Up to 64 number of bits per word
CK<nw-1>
WA<nw-1>[m-1:0]
REN<nr-1>
OEN<nr-1>
DOUT<nr-1>[b–1:0]
arfram_hd_<nr>r<nw>w_<w>x<b>m<y>
RA<nr-1>[m-1:0]
NOTES:
1. Words(w) is the number of words.
2. Bpw(b) is the number of bits per word.
3. Ymux(y) is one of the column mux types.
4. Writes(nw) is the number of write ports(1-to-2).
6. m =
log
2
w
5. Reads(nr) is the number of read ports(1-to-2).
WEN<nw-1>
DI<nw-1>[b-1:0]