
IBM13M32734BCC
Preliminary
32M x 72 2 Bank Registered SDRAM Module
88H5165.E24449
4/98
IBM Corporation. All rights reserved.
Use is further subject to the provisions at the end of this document.
Page 1 of 19
Features
168-Pin Registered 8-Byte Dual In-Line Memory
Module
32Mx72 Synchronous DRAM DIMM
Performance (Registered Mode):
Intended for 66/100MHz and PC100 applica-
tions
All inputs and outputs are LVTTL (3.3V) compat-
ible
Single 3.3V
±
0.3V Power Supply
Single Pulsed RAS interface
SDRAMs have four internal banks
Module has two physical banks
Fully Synchronous to positive Clock Edge
Programmable Operation:
- DIMM CAS Latency: 3, 4 (Registered
mode)
- Burst Type: Sequential or Interleave
- Burst Length: 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
12/10/2 Addressing (Row/Column/Bank)
4096 refresh cycles distributed across 64ms
Card size: 5.25" x 1.70" x 0.320"
5.25" x 2.70" x 0.320"
Gold contacts
SDRAM
S
in TSOJ 2-High Package
Serial Presence Detect with Write protect feature
Thermally enhanced DIMM available
Description
IBM13M32734BCC is a registered 168-Pin Syn-
chronous DRAM Dual In-Line Memory Module
(DIMM) organized as a 32Mx72 high-speed mem-
ory array. The DIMM uses 18 32Mx4 SDRAMs in
400 mil TSOJ stacked packages. The DIMM
achieves high-speed data-transfer rates of up to
100MHz by employing a prefetch/pipeline hybrid
architecture that synchronizes the output data to a
system clock.
Two module sizes are available: One with a stan-
dard height of 1.7”; the other with a one-inch-taller
form factor for thermal enhancement.
The DIMM is intended for use in applications oper-
ating from 66MHz to 100MHz (PC100) memory bus
speeds, and/or heavily loaded bus applications. All
control and address signals are re-driven through
registers to the SDRAM devices. The con-
trol/address input signals are latched in the register
on one rising clock edge and sent to the SDRAM
devices on the following rising clock edge (data
access is delayed by one clock).
A phase-lock loop (PLL) on the DIMM is used to re-
drive the clock signals to both the SDRAM devices
and the registers 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) controls all devices on the DIMM,
enabling the use of SDRAM power-down modes
(the stacked devices share a common CKE pin).
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.
-10
-360
(PC100)
4
100
10
7.7
Units
DIMM CAS Latency
f
CK
Clock Frequency
t
CK
Clock Cycle
t
AC
Clock Access Time
3
66
15
9.7
MHz
ns
ns
IBM11M4730C4M x 72 E12/10, 5.0V, Au.