40MX and 42MX FPGA Families
Up to 7-Input Function Plus D-Type Flip-Flop with Clear
Up to 7-Input Function Plus Latch
Up to 4-Input Function Plus Latch with Clear
Up to 8-Input Function (Same as C-Module)
Figure 1-3 • 42MX S-Module Implementation
A42MX24 and A42MX36 devices contain D-modules, which are arranged around the periphery of the
device. D-modules contain wide-decode circuitry, providing a fast, wide-input AND function similar to that
found in CPLD architectures (Figure 1-4). The D-module allows A42MX24 and A42MX36 devices to
perform wide-decode functions at speeds comparable to CPLDs and PALs. The output of the D-module
has a programmable inverter for active HIGH or LOW assertion. The D-module output is hardwired to an
output pin, and can also be fed back into the array to be incorporated into other logic.
Dual-Port SRAM Modules
The A42MX36 device contains dual-port SRAM modules that have been optimized for synchronous or
asynchronous applications. The SRAM modules are arranged in 256-bit blocks that can be configured as
32x8 or 64x4. SRAM modules can be cascaded together to form memory spaces of user-definable width
and depth. A block diagram of the A42MX36 dual-port SRAM block is shown in Figure 1-5.
The A42MX36 SRAM modules are true dual-port structures containing independent read and write ports.
Each SRAM module contains six bits of read and write addressing (RDAD[5:0] and WRAD[5:0],
respectively) for 64x4-bit blocks. When configured in byte mode, the highest order address bits (RDAD5
and WRAD5) are not used. The read and write ports of the SRAM block contain independent clocks
(RCLK and WCLK) with programmable polarities offering active HIGH or LOW implementation. The
SRAM block contains eight data inputs (WD[7:0]), and eight outputs (RD[7:0]), which are connected to
segmented vertical routing tracks.
The A42MX36 dual-port SRAM blocks provide an optimal solution for high-speed buffered applications
requiring FIFO and LIFO queues. The ACTgen Macro Builder within Microsemi's Designer software