29 of 30 May 12, 2010
Advance Information
IDT Confidential
Use in a Memory Module
In the Dual Inline Memory Module (DIMM) application, the TSE2002B3C is soldered directly onto the printed circuit module. The three Select
Address inputs (SA0, SA1, SA2) must be connected to V
SSSPD
or V
DDSPD
directly (that is without using a pull-up or pull-down resistor) through the
DIMM socket (as shown in the Unique Addressing table). The pull-up resistors needed for normal behavior of the I
2
C bus are connected on the I
2
C
bus of the mother-board
Unique Addressing of SPDs in DIMM Applications
Note: 0 = V
SSSPD
, 1 = V
DDSPD
.
The Event pin is expected to be used in a wire-OR configuration with a pull-up resistor to VDDSPD on the motherboard. In this configuration,
EVENT should be programmed for the active low mode. Also note that comparator mode or TCRIT-only mode for EVENT on a wire-OR bus will show
the combined results of all devices wired to the EVENT signal.
Programming the TSE2002B3C
The situations in which the TSE2002B3C is programmed can be considered under two headings:
• When the DIMM is isolated (not inserted on the PCB motherboard)
• When the DIMM is inserted on the PCB motherboard
DIMM Isolated
With specific programming equipment, it is possible to define the TSE2002B3C content, using Byte and Page Write instructions, and its
write-protection using the SWP and CWP instructions. To issue the SWP and CWP instructions, the DIMM must be inserted in the application-specific
slot where the SA0 signal can be driven to VHV during the whole instruction. This programming step is mainly intended for use by DIMM makers,
whose end application manufacturers will want to clear this write-protection with the CWP on their own specific programming equipment, to modify the
lower 128 Bytes, and finally to set permanently the write-protection with the PSWP instruction.
DIMM Inserted in the Application Mother Board
As the final application cannot drive the SA0 pin to V
HV
, the only possible action is to freeze the write-protection with the PSWP instruction. Refer
to the Acknowledge When Writing Data or Defining Write Protection table on how the Ack bits can be used to identify the write-protection status.
DIMM Position SA2 SA1 SA0
0000
1001
2010
3011
4100
5101
6110
7111
