HY51V64404A,HY51V65404A
NOTE
1. An initial pause of 200ms is required after power-up followed by 8 /RAS-only refresh cycles before proper device
operation is achieved. In case of using internal refresh counter, a minimum of 8 /CAS- before-/RAS initialization
cycles instead of 8 /RAS-only refresh cycles are required. The device should be carefully initialized to be prevented
from being entered into multi bit parallel test mode during initialization.
2. If /RAS=VSS during power-up, the HY51V64404A, HY51V65404A could begin an active cycle. This condition results in
higher current than necessary current which is demanded from the power supply during power-up.
3. It is recommended that /RAS and /CAS track with Vcc during power-up or be held at a valid VIH in order to minimize
the power-up current.
4. 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.
5. Measured at VOH=2.0V and VOL=0.8V with a load equivalent to 1TTL loads and 100pF.
6. Either tRCH or tRRH must be satisfied for a read cycle.
7. These parameters are referenced to /CAS leading edge in early write cycles and to /WE leading edge in read-modify-
write cycles and late write cycle.
8. tWCS, tRWD, tCWD, tAWD and tCPWD are not restrictive operating parameters. They are included in the data sheet as
electrical characteristics only. If tWCS ³ tWCS(min.), the cycle is an early write cycle and data out pin will remain open
circuit (high impedance) through the entire cycle. If tRWD ³ tRWD(min.), tCWD ³ tCWD(min.), tAWD ³ tAWD(min), and tCPWD ³
tCPWD(min.), the cycle is a read-modify-write cycle and data out 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.
9. Operation within the tRCD(max.) limit ensures 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 by tCAC.
10.Operation within the tRAD(max.) limit ensures 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.tREF(max)=128ms is applied to L-parts .
12.A burst of 4096(4k refresh part) /RAS-only refresh cycles must be executed within 64ms (128ms for L-parts) after
exiting self refresh.A burst of 8192(8k refresh part) /RAS-only refresh cycles must be executed within 64ms (128ms for
L-parts) after exiting self refresh.(CBR refresh & Hidden refresh : 4K cycle/64ms)
13.tASC,tCAH are referenced to the earlier /CAS falling edge.
CAPACITANCE
(TA = 0°C to 70°C , VCC = 3.3 ± 0.3V, VSS = 0V, f = 1MHz, unless otherwise noted.)
Symbol
Parameter
Input Capacitance (A0~A12)
Typ.
Max
Unit
pF
CIN1
-
-
-
5
7
7
CIN2
CDQ
Input Capacitance (/RAS, /CAS, /WE, /OE)
Data Input / Output Capacitance (DQ0~DQ7)
pF
pF
16Mx4,EDO DRAM
Rev.10/Sep.98
10