
COMPILED MEMORY
CHARACTERISTICS FOR TIMING AND POWER
Samsung ASIC
5-3
STD130
A two-dimensional timing characteristics table look-up model has been adopted to yield more accuracy.
Based on the combination of input slopes and output loads, the propagation delay is measured from the
input crossing 50% V
DD
to the output crossing 50% V
DD
. The timing values reported in the tables are also
taken from the same voltage level as the switching characteristics with 0.2ns for input slope and 10SL
(Standard Load) for output load.
The power consumption for read and write modes is measured for on input slope of 0.2ns, an output load of
10SL and an input switching activity factor of 0.5. The total power consumption can be calculated by the
following equation:
P
total
= ((SA
read
×
P
read
) + (SA
write
×
P
write
))
×
f
MAX
Where,
P
total
is the total power consumption in microwatts
P
read
is the read power consumption in microwatts per MHz
P
write
is the write power consumption in microwatts per MHz
SA
read
is the read access ratio on every cycle
SA
write
is the write access ratio on every cycle
f
MAX
is the RAM clock frequency in MHz.
The value of
SA
read
or
SA
write
is between 0 and 1. However, the sum of
SA
read
and
SA
write
must be less than
or equal to 1.
The power values reported in the tables are also taken from 50% switching activity, SA=0.5. For compiled
memory, the read power consumption, the write power consumption and the standby power consumption
are available. The standby power consumption is measured on the condition that CSN (Chip Select
Negative) disabled and for other signals in their normal operating mode except that OEN (Output Enable
Negative) is held low. If any of the signals are not active during standby mode, the standby power is near
zero and only static leakage power consumed. In dual-port memories, the power consumption is measured
with only one port active and the other port isolated.