HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 473

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

Notes: 1.
Figure 19.12 (a) DRAM Bus Cycle (Short-Pitch, High-Speed Page Mode: Read)
WRH, WRL ,
AD15–AD0
WR (Read)
DPH, DPL
RD(Read)
2.
3.
4.
5.
A21–A0
DACK0
DACK1
(Read)
(Read)
RAS
CAS
For t
of t
It is not necessary to meet the t
met.
For t
It is not necessary to meet the t
met.
For t
It is not necessary to meet the t
met.
t
t
RDH
RDH
CK
cyc
is measured from A21—A0 or CAS, whichever is negated first.
is measured from A21—A0, RAS, or CAS, whichever is negated first.
CAC1
ACC1
RAC1
– t
, use t
, use t
, use t
AD
– t
T
p
ASC
cyc
cyc
cyc
t
RASD1
– t
– 30 instead of t
t
RAC1
t
AD
0.65 – 19 (for 35% duty) or t
1.5 – 20 instead of t
RDS
T
*
.
r
Row address
3
t
ACC1
t
RDD
t
AD
*
t
Column address
T
2
t
DACD1
CAC1
RDS
RDS
RDS
c
t
ASC
t
cyc
RDS
specification as long as the t
specification as long as the t
specification as long as the t
*
– t
1
t
RSD
t
t
DACD2
RDH
AD
Column address
t
t
cyc
ACP
CP
T
– t
c
*
4
RDS
1.5 – t
.
cyc
Column address
T
RASD1
c
0.5 – 19 (for 50% duty) instead
– t
Column address
RDS
T
c
.
CAC1
ACC1
RAC1
t
t
RDH
RASD2
specification is
specification is
specification is
HITACHI 465
*
5