HM5116405 Series, HM5117405 Series
Refresh (HM5117405 Series)
Parameter
Symbol
tREF
Max
32
Unit
ms
Notes
Refresh period
2048 cycles
2048 cycles
Refresh period (L-version)
tREF
128
ms
Notes: 1. AC measurements assume tT = 2 ns.
2. An initial pause of 200 µs is required after power up followed by a minimum of eight initialization
cycles (any combination of cycles containing RAS-only refresh or CAS-before-RAS refresh). If
the internal refresh counter is used, a minimum of eight CAS-before-RAS refresh cycles are
required.
3. Operation with 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
.
4. Operation with 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 exclusively by tAA.
5. Either tOED or tCDD must be satisfied.
6. Either tDZO or tDZC must be satisfied.
7. VIH (min) and VIL (max) are reference levels for measuring timing of input signals. Also, transition
times are measured between VIH (min) and VIL (max).
8. Assumes that tRCD ≤ tRCD (max) and tRAD ≤ tRAD (max). If tRCD or tRAD is greater than the maximum
recommended value shown in this table, tRAC exceeds the value shown.
9. Measured with a load circuit equivalent to 1 TTL loads and 100 pF.
10. Assumes that tRCD ≥ tRCD (max) and tRCD + tCAC (max) ≥ tRAD + tAA (max).
11. Assumes that tRAD ≥ tRAD (max) and tRCD + tCAC (max) ≤ tRAD + tAA (max).
12. Either tRCH or tRRH must be satisfied for a read cycles.
13. tOFF (max) and tOEZ (max) define the time at which the outputs achieve the open circuit condition
and are not referred to output voltage levels.
14. tWCS, tRWD, tCWD, tAWD and tCPW are not restrictive operating parameters. They are included in the
data sheet as electrical characteristics only; if tWCS ≥ tWCS (min), the cycle is an early write cycle
and the data out pin will remain open circuit (high impedance) throughout the entire cycle; if tRWD
≥ tRWD (min), tCWD ≥ tCWD (min), and tAWD ≥ tAWD (min), or tCWD ≥ tCWD (min), tAWD ≥ tAWD (min) and tCPW
tCPW (min), the cycle is a read-modify-write and the data output will contain data read from the
selected cell; if neither of the above sets of conditions is satisfied, the condition of the data out
(at access time) is indeterminate.
≥
15. These parameters are referred to CAS leading edge in early write cycles and to WE leading
edge in delayed write or read-modify-write cycles.
16. tRASP defines RAS pulse width in EDO page mode cycles.
17. Access time is determined by the longest among tAA, tCAC and tCPA
.
18. In delayed write or read-modify-write cycles, OE must disable output buffer prior to applying data
to device.
19. The 16M DRAM offers a 16-bit time saving parallel test mode. Address CA0 and CA1 for the 4M
×4 are don’t care during test mode. Test mode is set by performing a WE-and-CAS-before-RAS
(WCBR) cycle. In 16-bit parallel test mode, data is written into 4 bits in parallel at each I/O (I/O1
to I/O4) and read out from each I/O.
If 4 bits of each I/O are equal (all 1s or 0s), data output pin is a high state during test mode read
cycle, then the device has passed. If they are not equal, data output pin is a low state, then the
device has failed.
Data Sheet E0151H10
15
ELPIDA [ ELPIDA MEMORY ]
