SMJ320MCM42C, SMJ320MCM42D

DUAL SMJ320C40 MULTICHIP MODULE

SGKS001B – JULY 1997 – REVISED FEBRUARY 2000

10

POST OFFICE BOX 1443

application note

For the ’MCM42C, the location of the local memory has changed from that of the ’MCM42D. In addition, to make

proper use of the local memory, it is necessary to understand how it is controlled.

In the case of the ’MCM42C, the lower 128K of memory is controlled by LSTRB0, while the upper 128K of

memory is controlled by LSTRB1. Since the upper 128K begins at address 1000000h, it is necessary to load

the value 10111 (binary) into the STRB ACTIVE area (bits 28–24) of the local memory interface control register

(LMICR). This process ensures that the ’C40 uses LSTRB0 to control the lower 128K and LSTRB1 to control

the upper 128K.

In the case of the ’MCM42D, LSTRB0 controls the entire 128K. The value loaded into the STRB ACTIVE area

of the LMICR after reset is sufficient to control the memory. This value is 1110, and tells the ’C40 that the entire

local memory is controlled by LSTRB0.

This subject is discussed in depth in Chapter 9 of the

1996 TMS320C4x User’s Guide (literature number

SPRU063). In particular, section 9.3 discusses the proper use of the memory interface control registers.

reference documentation and data sheet scope

The SMJ320MCM42 is qualified to MIL-PRF-38535. Electrical continuity of the module is ensured through the

use of IEEE-1149.1-compatible boundary-scan testing and functional checkout of the local SRAM space.

KGD refers to TI known-good-die strategy. TI KGDs are fully tested over the military temperature range per

MIL-PRF-38535 QML. Electrical tests ensure compliance of the ’C40 KGD components to the SMJ320C40 data

sheet (literature number SGUS017) over the operating temperature range. Module timings are virtually

unchanged from the SMJ320C40 data sheet timings. An SMJ320C40 data sheet is provided for customer

reference only and does not imply MCM compliance to published timings.

For a description of the ’C40 operation and application information, see the

TMS320C4x User’s Guide (literature

number SPRU063).