ACEX1K datasheet(13/86 Pages) ALTERA

13 / 86 page

Altera Corporation

ACEX 1K Programmable Logic Device Family Data Sheet

If necessary, all EABs in a device can be cascaded to form a single RAM

block. EABs can be cascaded to form RAM blocks of up to 2,048 words

without impacting timing. Altera software automatically combines EABs

to meet a designer’s RAM specifications.

EABs provide flexible options for driving and controlling clock signals.

Different clocks and clock enables can be used for reading and writing to

the EAB. Registers can be independently inserted on the data input, EAB

output, write address, write enable signals, read address, and read enable

signals. The global signals and the EAB local interconnect can drive

write-enable, read-enable, and clock-enable signals. The global signals,

dedicated clock pins, and EAB local interconnect can drive the EAB clock

signals. Because the LEs drive the EAB local interconnect, the LEs can

control write-enable, read-enable, clear, clock, and clock-enable signals.

An EAB is fed by a row interconnect and can drive out to row and column

interconnects. Each EAB output can drive up to two row channels and up

to two column channels; the unused row channel can be driven by other

LEs. This feature increases the routing resources available for EAB

outputs (see Figures 2 and 4). The column interconnect, which is adjacent

to the EAB, has twice as many channels as other columns in the device.

Logic Array Block

An LAB consists of eight LEs, their associated carry and cascade chains,

LAB control signals, and the LAB local interconnect. The LAB provides

the coarse-grained structure to the ACEX 1K architecture, facilitating

efficient routing with optimum device utilization and high performance.

Figure 7 shows the ACEX 1K LAB.

ACEX1K датащи(PDF) 13 Page - Altera Corporation