SEC ASIC
5-59
STD80/STDM80
DPSRAMA Gen
Dual-Port Synchronous RAM Generator – Alternative
Logic Symbol
Function Description
DPSRAMA is a dual-port synchronous static RAM. When WEN1 is high and CK1 rises, DOUT1 [ ] presents
data stored in the location addressed by A1 [ ]. When WEN1 is low and CK1 falls, or when CK1 is high and
WEN1 rises, the value of DI1 [ ] is written into the location addressed by A1 [ ]. CSN1 is used to
enable/disable CK1. OEN1 is used to enable/disable tri-state drivers of DOUT1 [ ]. The functionality of port2
is the same to port1. The port1 and port2 function independently each other.
DPSRAMA is an alternative of DPSRAM. The major difference of these two RAMs is the timing of read and
write. DPSRAMA reads and writes at different edge of the clock since DPSRAM reads and writes at the
same edge of the clock.
Generators and Cell Configurations
DPSRAMA Gen. generates layout, netlist, symbol and functional & timing model of DPSRAMA. The layout
of DPSRAMA is an automatically generated array of custom, pitch-matched leaf cells. To customize the
configuration of DPSRAMA, you can give certain values to following three generator parameters:
Number of words (w)
Number of bits per word (b)
Lower address decoder type (y).
The valid range of these parameters is specified in the following table:
Parameters
YMUX = 2
4
512
2
1
128
1
YMUX = 4
8
1024
4
1
64
1
YMUX = 8
16
2048
8
1
32
1
YMUX = 16
32
4096
16
1
16
1
YMUX = 32
64
8192
32
1
8
1
Words (w)
Min
Max
Step
Min
Max
Step
Bpw (b)
NOTES:
1. Words (w) is the number of words in DPSRAMA.
2. Bpw (b) is the number of bits per word.
3. Ymux (y) is one of the lower address decoder types.
4. m =
log
2
w
– 1
CK1
CK2
CSN1
CSN2
WEN1
WEN2
OEN1
OEN2
A1 [m:0]
A2 [m:0]
DI1 [b–1:0]
DI2 [b–1:0]
dpsrama<w>x<b>m<y>
DOUT1 [b–1:0]
DOUT2 [b–1:0]
Features
Synchronous operation
Read initiated at rising edge of clock
Write completed at falling edge of clock
Possible read modified write cycle
Stand-by (power down) mode available
Tri-state output
Separated data I/O
Low noise output circuit
Possible bi-directional operation
Flexible aspect ratio
Up to 64K bits capacity
Up to 8K number of words
Up to 128 number of bits per word