MT49H64M9HT-25E:A Micron Technology Inc, MT49H64M9HT-25E:A Datasheet - Page 40

• Manufacturer Part Number: MT49H64M9HT-25E:A
• Manufacturer: Micron Technology Inc
• Type: RLDRAMr

Specifications of MT49H64M9HT-25E:A

• Organization: 64Mx9
• Address Bus: 25b
• Operating Supply Voltage (typ): 1.8V
• Package Type: FBGA
• Operating Temp Range: 0C to 95C
• Operating Supply Voltage (max): 1.9V
• Operating Supply Voltage (min): 1.7V
• Supply Current: 675mA
• Pin Count: 144
• Mounting: Surface Mount
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Compliant

AUTO REFRESH (AREF)
Figure 16:
PDF: 09005aef80a41b46/Source: 09005aef809f284b
RLDRAM_II_CIO_Core.fm - Rev. D 6/09 EN
AUTO REFRESH Command
AREF is used to perform a REFRESH cycle on one row in a specific bank. Because the row
addresses are generated by an internal refresh counter for each bank, the external
address balls are “Don’t Care.” The bank addresses must be provided during the AREF
command. The bank address is needed during the AREF command so refreshing of the
part can effectively be hidden behind commands to other banks. The delay between the
AREF command and a subsequent command to the same bank must be at least
Within a period of 32ms (
device, the RLDRAM requires 128K cycles at an average periodic interval of 0.24µs MAX
(actual periodic refresh interval is 32ms/16K rows/8 = 0.244µs). To improve efficiency,
eight AREF commands (one for each bank) can be posted to the RLDRAM at periodic
intervals of 1.95µs (32ms/16K rows = 1.95µs). Figure 31 on page 55 illustrates an example
of a refresh sequence.
ADDRESS
ADDRESS
BANK
WE#
REF#
CK#
CS#
CK
576Mb: x9, x18, x36 2.5V Vext, 1.8V Vdd, HSTL, CIO, RLDRAM II
DON’T CARE
BA
t
REF), the entire device must be refreshed. For the 576Mb
40
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2004 Micron Technology, Inc. All rights reserved.
Commands
t
RC.