第二章 大规模可编程器件.ppt

* cyclone每个EAB可提供4096(4608 with parity)bits， ram / rom / dual port RAM / FIFO可或组合 The memory address depths and output widths can be configured as 4,096 × 1, 2,048 × 2, 1,024 × 4, 512 × 8 (or 512 × 9 bits), 256 × 16 (or 256 × 18 bits), and 128 × 32 (or 128 × 36 bits). The 128 × 32- or 36-bit configuration is not available in the true dual-port mode. Mixed-width configurations are also possible, allowing different read and write widths. Control Signals M4K Interface The M4K blocks allow for different clocks on their inputs and outputs. Either of the two clocks feeding the block can clock M4K block registers (renwe, address, byte enable, datain, and output registers). Only the output register can be bypassed. The six labclk signals or local interconnects can drive the control signals for the A and B ports of the M4K block. LEs can also control the clock_a, clock_b, renwe_a, renwe_b, clr_a, clr_b, clocken_a, and clocken_b signals, as shown in Figure2–15. The R4, C4, and direct link interconnects from adjacent LABs drive the M4K block local interconnect. The M4K blocks can communicate with LABs on either the left or right side through these row resources or with LAB columns on either the right or left with the column resources. Up to 10 direct link input connections to the M4K block are possible from the left adjacent LABs and another 10 possible from the right adjacent LAB. M4K block outputs can also connect to left and right LABs through 10 direct link interconnects each. Figure2–16 shows the M4K block to logic array interface. The IOEs are located in I/O blocks around the periphery of the Cyclone device. There are up to three IOEs per row I/O block and up to three IOEs per column I/O block (column I/O blocks span two columns). The row I/O blocks drive row, column, or direct link interconnects. The column I/O blocks drive column interconnects. Figure2–28 shows how a row I/O block connects to the logic array. Figure2–29 shows how a column I/