JEM_DIMM / SODIMM Module
This module is intended for the test of DDR3 SDRAM.
Popular devices include MT18JSF25672AZ – 2GB and MT18JSF51272AZ – 4GB
The StarTest JEM_DIMM/SODIMM/SORDIMM modules main features are:
- Performs both interconnect and cluster tests on DIMM/SODIMM memory sockets
- Tests for opens on PWR and GND pins of the DIMM/SODIMM sockets
- Each I/O pin is independently controlled for sense, drive, bi-directional, and tri-state function
- Keyed flat connector compatibility
- Hot Swap: each module may be connected/disconnected between tests without switching power off
- Equipped with a JTAG/IEEE 1149.1 AND IEEE 1149.7 Test Access Port (TAP) externally (via cable) or internally (via socket) accessible
- Full software support both for usage and the self-test
The primary function of the JTAG External Modules (JEM) for the DIMM/SODIMM Socket Cluster Test is to provide test access to off-board signals that otherwise could not be accessed by a JTAG test system, and to strengthen the memory-independent JTAG testing for the assembly correctness of the following socket types:
- DIMM (Dual In-line Memory Module), miniDIMM, microDIMM, VLP DIMM sockets - JEM_DIMM184 is IEEE 1149.7 Compliant
- SODIMM (Small Outline Dual In-line Memory Module) sockets
- SORDIMM (Small Outline Registered Dual In-line Memory Module) sockets
- SOCDIMM (Small Outline Clocked Dual In-line Memory Module) sockets
- VLP SORDIMM (Very Low Profile Small Outline Registered Dual In-line Memory Module) sockets
- FBDIMM (Fully Buffered Dual In-line Memory Module) sockets
For many designs, JTAG test has adequate access to on-board signals, but signals that go off the board often can not be tested. By adding JTAG access to memory socket off-board signals, a JEM_DIMM/SODIMM module can increase the board's fault coverage, possibly reducing the need for developing alternative tests to reach the required test coverage level. The JEM_DIMM/SODIMM module provides a number of JTAG accessible individually controlled test channels that can be used to control and observe signals that go off the board.
It is possible to test the DIMM/SODIMM socket assembly correctness by inserting a DIMM/SODIMM memory module into the corresponding socket and executing a JTAG memory-pattern test. For the usage of this technique the specific memory JTAG test module have to be utilized for write/read memory operations and test results diagnostics.