
  IBM13M8734HCD
8M x 72 1 Bank Registered/Buffered SDRAM Module
19L7291.E93875A
8/99
IBM Corporation. All rights reserved.
Use is further subject to the provisions at the end of this document.
Page 1 of 21
Features
 168-Pin Registered 8-Byte Dual In-Line Memory
Module
 8Mx72 Synchronous DRAM DIMM
 Performance:
-10
Device Latency
3
Clock Frequency
66
Clock Access Time
8.2
 Intended for 66/100MHz and PC100 applica-
tions
 Inputs and outputs are LVTTL (3.3V) compatible
 Single 3.3V
 ±
 0.3V Power Supply
 Single Pulsed RAS interface
 SDRAMs have four internal banks
 Module has one physical bank
 Fully Synchronous to positive Clock Edge
 Programmable Operation:
- DIMM CAS Latency:3, 4 (Registered
mode),
- Burst Type: Sequential or Interleave
- Burst Length: 1, 2, 4, 8, Full-Page (Full-
Page supports Sequential burst only)
- Operation: Burst Read and Write
or Multiple Burst Read with Single Write
 Data Mask for Byte Read/Write control
 Auto Refresh (CBR) and Self Refresh
 Automatic and controlled Precharge Commands
 Suspend Mode and Power Down Mode
 12/9/2 Addressing (Row/Column/Bank)
 4096 refresh cycles distributed across 64ms
 Card size: 5.25" x 1.5" x 0.157"
 Gold contacts
 SDRAM
S
 in TSOP - Type II Package
 Serial Presence Detect with Write protect feature
2, 3 (Buffered mode)
Description
IBM13M8734HCD is a registered 168-Pin Synchro-
nous DRAM Dual In-Line Memory Module (DIMM)
organized as an 8Mx72 high-speed memory array.
The DIMM uses nine 8Mx8 SDRAMs in 400 mil
TSOP packages. The DIMM achieves high-speed
data-transfer rates of up to 100 MHz by employing a
prefetch/pipeline hybrid architecture that synchro-
nizes the output data to a system clock.
The DIMM is intended for use in applications oper-
ating from 66MHz to 100 MHz, PC100, memory bus
speeds, and/or heavily loaded bus applications. All
control and address signals are re-driven through
registers/buffers to the SDRAM devices. The DIMM
can be operated in either registered mode (REGE
pin tied high), where the control/address input sig-
nals are latched in the register on one rising clock
edge and sent to the SDRAM devices on the follow-
ing rising clock edge (data access is delayed by one
clock), or in buffered mode (REGE pin tied low)
where the input signals pass through the regis-
ter/buffer to the SDRAM devices on the same clock.
XTK simulation models of the DIMM are available to
determine which mode to design for.
A phase-lock loop (PLL) on the DIMM is used to re-
drive the clock signals to the SDRAM devices to
minimize system clock loading. (CK0 is connected
to the PLL, and CK1, CK2, and CK3 are terminated
on the DIMM.) A single clock enable (CKE0) con-
trols all devices on the DIMM, enabling the use of
SDRAM power-down modes.
Prior to any access operation, the device CAS
latency and burst type/length/operation type must
be programmed into the DIMM by address inputs
A0-A9 using the mode register set cycle. The DIMM
CAS latency when operated in buffered mode is the
same as the device CAS latency as specified in the
SPD EEPROM. The DIMM CAS latency when oper-
ated in registered mode is one clock later due to the
address and control signals being clocked to the
SDRAM devices.
The DIMM uses serial presence detects imple-
mented via a serial EEPROM using the two-pin IIC
protocol. The first 128 bytes of serial PD data are
programmed and locked by the DIMM manufac-
turer. The last 128 bytes are available to the cus-
tomer and may be write protected by providing a
high level to pin 81 on the DIMM. An on-board pull-
down resistor keeps this in the write-enable mode.
All IBM 168-pin DIMMs provide a high-performance,
flexible 8-byte interface in a 5.25" long space-saving
footprint.
-260
2
100
7.2
-360
2
66
10.2
-360 Units
3
100
7.2
MHz
ns
.
Discontinued (4/1/00 - last order; 7/31/00 - last ship)