SigMem-PC/104 Memory Expansion Board

The SigMem-PC/104 Memory Expansion board adds zero wait-state SRAM expansion for the SigC44, SigC54x, and other PC/104 DSP/data acquisition boards. It uses the standard 100-pin "Global Bus" connector defined for SigXXX PC/104 boards to provide a high-speed data path directly to the DSP processor, without being impacted by PC/104 bus traffic.

SigMem-PC/104 Board Feature Summary

• 128k, 256k, 768k, or 1024k x 32 of zero wait-state SRAM; power-down mode (i.e. both ~CS and ~WR high) enabled when SRAMs are not being accessed

• C4x boards see the expansion memory as global SRAM, allowing these boards to simultaneously access local SRAM using parallel instructions, in order to improve algorithm efficiency

• tested and available with either Samsung or Cypress "center" pwr and gnd 128k x 32 or 512k x 32 SRAM parts. Low power devices, with slower access time (for example 55 or 70 nsec), may also be used.

• can be stacked under or on top of processor board; contains JTAG cut-out, to allow convenient access to JTAG debug header on processor board if memory expansion board is stacked on top

• Global Bus 100-pin connector is physically opposed to PC/104 connector, and provides increased mechanical reliablity and resistance to shock and vibration

• flexible onboard EPLD allows memory organization to be modified; for example, fixed-point PC/104 boards can access the memory as x16 organization

• provides Global Bus connector to allow standard SigXXX PC/104 board peripheral and digital I/O expansion offered by the Global Bus. The SigMem board uses only a section of expansion address space, reserving remaining space for user-defined applications.