K4E170811D Datasheet, PDF (8/21 Pages) Samsung semiconductor – 2M x 8Bit CMOS Dynamic RAM with Extended Data Out

K4E170811D, K4E160811D
K4E170812D, K4E160812D
CMOS DRAM
NOTES
1. An initial pause of 200us is required after power-up followed by any 8 RAS-only refresh or CAS-before-RAS refresh cycles
before proper device operation is achieved.
2. VIH(min) and VIL(max) are reference levels for measuring timing of input signals. Transition times are measured between
VIH(min) and VIL(max) and are assumed to be 2ns for all inputs.
3. Measured with a load equivalent to 2 TTL(5V)/1 TTL(3.3V) loads and 100pF.
4. Operation within the tRCD(max) limit insures that tRAC(max) can be met. tRCD(max) is specified as a reference point only.
If tRCD is greater than the specified tRCD(max) limit, then access time is controlled exclusively by tCAC.
5. Assumes that tRCD≥tRCD(max).
6. This parameter defines the time at which the output achieves the open circuit condition and is not referenced to Voh or Vol.
7. tWCS, tRWD, tCWD and tAWD are non restrictive operating parameters. They are included in the data sheet as electrical charac-
teristics only. If tWCS≥tWCS(min), the cycle is an early write cycle and the data output will remain high impedance for the dura-
tion of the cycle. If tCWD≥tCWD(min), tRWD≥tRWD(min) and tAWD≥tAWD(min), then the cycle is a read-modify-write cycle and the
data output will contain the data read from the selected address. If neither of the above conditions is satisfied, the condition
of the data out is indeterminate.
8. Either tRCH or tRRH must be satisfied for a read cycle.
9. These parameters are referenced to CAS falling edge in early write cycles and to W falling edge in OE controlled write cycle
and read-modify-write cycles.
10. Operation within the tRAD(max) limit insures that tRAC(max) can be met. tRAD(max) is specified as a reference point only.
If tRAD is greater than the specified tRAD(max) limit, then access time is controlled by tAA.
11. These specifications are applied in the test mode.
12. In test mode read cycle, the value of tRAC, tAA, tCAC is delayed by 2ns to 5ns for the specified values. These parameters
should be specified in test mode cycles by adding the above value to the specified value in this data sheet.
13. _{tASC≥6ns, Assume tT = 2.0ns}
14. If RAS goes high before CAS high going, the open circuit condition of the output is achieved by CAS high going. If CAS goes
high before RAS high going, the open circuit condition of the output is achieved by RAS high going.
15. If tRASS≥100us, then RAS precharge time must use tRPS instead of tRP.
16. For RAS-only refresh and burst CAS-before-RAS refresh mode, 4096(4K)/2048(2K) cycles of burst refresh must be exe-
cuted within 64ms/32ms before and after self refresh, in order to meet refresh specification.
17. For distributed CAS-before-RAS with 15.6us interval CAS-before-RAS refresh should be executed with in 15.6us immedi-
ately before and after self refresh in order to meet refresh specification.