Semiconductor MSC23440D
Notes: 1. A start- up delay of 200µs is required after power-up, followed by a mi nimum of eight ini tializ ation cycles
(/RA S only refr esh or / CA S befor e /RAS refr esh) before pr oper device operat ion i s achieved.
2. The AC c har ac teri stics assumes tT = 5ns.
3. VIH(Min. ) and VIL(Max .) are ref erence l ev els for measuring input timi ng signals. Transiti on ti me (tT) are
m easured bet ween VIH and VIL.
4. This parameter i s measured wi th a load c ircuit equivalent to 2TT L loads and 100pF.
5. Operation within the tRCD(M ax. ) li mit ensures that t RAC(Max . ) can be met.
tRCD(Max.) is s pecified as a reference point only . If tRCD is greater than the s pecified tRCD(Max.) limit, then
the acc ess ti me is controlled by tCAC.
6. Operation within the tRAD(Max.) li mit ensures that tRAC(Max . ) can be met.
tRAD(Max.) is s pecified as a reference point only. If tRAD is greater than the specified tRAD(Max.) limit, the n
the acc ess ti me is controlled by tAA.
7. tOFF(Max.) and tOEZ(Max.) define the time at which the output achieves the open circuit condition and are
not refer enc ed to output voltage levels.
8. tRCH or tRRH must be satisfied for a read cycle.
9. tWCS, tCWD, tRWD, tAWD and tCPWD are not restri ctiv e operati ng paramet ers. T hey are i ncluded in the data
sheet as elect r ical characteri stics only. I f tWCS ≥ tWCS(Min.), the cycle is an early write cycle and t he data
out will remain open circuit (high impedance) throughout the entire cycle. If tCWD ≥ tCWD(Min.), tRWD ≥
tRWD(Min.), t AWD ≥ tAWD(Min.) and tCPWD ≥ tCPWD(Mi n. ), the cycle is a read modify wri t e cycle and data out
will contain data read from the selected cell; if neither or the abov e sets of conditions is satisfied, the
condi tions of the data out (at access time) is indet er minate.
10. These parameters are referenced to /CAS leading edge in an early write cycle, and to /WE leading edge
in an / OE control wri te cycle or a read modi fy write cycle.
11. The test mode is initiated by performing a /WE and /CAS before /RAS refresh cycle. This mode is
latched and remains in effect until the exit cycle is generated. The test mode specified in this data sheet
is an 8-bi t parall el test function. CA0, CA1 and CA10 are not used. In a read cycl e, if all internal bits are
equal, the DQ pin w ill ind ica te a h igh le vel. If an y in ter na l b its ar e n o t equal, the DQ pin will in dic at e a low
level. T he test mode is clear ed and the memory device returned t o its normal operati ng state by a /RAS
only refresh or /CAS bef ore /RAS ref resh cycle.
12. In a test mode read cycle, the value of access time parameters is delayed for 5ns for the specified value.
These parameters should be specified in test mode cycle by adding the abov e value to the specified
value in this data sheet.