IS43R32400D-5BL ISSI, Integrated Silicon Solution Inc, IS43R32400D-5BL Datasheet - Page 37

• Manufacturer Part Number: IS43R32400D-5BL
• Manufacturer: ISSI, Integrated Silicon Solution Inc
• Type: DDR SDRAMr

Specifications of IS43R32400D-5BL

• Organization: 4Mx32
• Density: 128Mb
• Address Bus: 14b
• Access Time (max): 700ps
• Maximum Clock Rate: 200MHz
• Operating Supply Voltage (typ): 2.6V
• Operating Temp Range: 0C to 70C
• Operating Supply Voltage (max): 2.7V
• Operating Supply Voltage (min): 2.5V
• Supply Current: 185mA
• Pin Count: 144
• Mounting: Surface Mount
• Operating Temperature Classification: Commercial
• Lead Free Status / RoHS Status: Compliant

IS43R32400D, IS43R16800D
READ to READ
Data from a read burst may be concatenated or truncated by a subsequent READ command. The first data from the
new burst follows either the last element of a completed burst or the last desired element of a longer burst that is
being truncated. The new READ command should be issued X cycles after the first READ command, where X equals
the number of desired data-out element pairs (pairs are required by the 2n prefetch architecture).
A READ command can be initiated on any clock cycle following a previous READ command. Full-speed random read
accesses within a page or pages can be performed as shown in Figure Random Read Bursts.
READ BURST TERMINATE
Data from any READ burst may be truncated with a BURST TERMINATE command. The BURST TERMINATE latency
is equal to the read (CAS) latency, i.e., the BURST TERMINATE command should be issued X cycles after the READ
command where X equals the desired data-out element pairs.
READ to WRITE
Data from READ burst must be completed or truncated before a subsequent WRITE command can be issued. If
truncation is necessary, the BURST TERMINATE command must be used, as shown in Figure Read to Write for the
case of nominal tDQSS.
READ to PRECHARGE
A Read burst may be followed by or truncated with a PRECHARGE command to the same bank (provided Auto
Precharge was not activated). The PRECHARGE command should be issued X cycles after the READ command,
where X equal the number of desired data-out element pairs.
Following the PRECHARGE command, a subsequent command to the same bank cannot be issued until tRP is met.
Note that part of the row precharge time is hidden during the access of the last data-out elements.
In the case of a Read being executed to completion, a PRECHARGE command issued at the optimum time (as
described above) provides the same operation that would result from Read burst with Auto Precharge enabled. The
disadvantage of the PRECHARGE command is that it requires that the command and address buses be available at
the appropriate time to issue the command. The advantage of the PRECHARGE command is that it can be used to
truncate bursts.
Integrated Silicon Solution, Inc.
37
Rev. 00D
06/22/09