National Instruments DP8400 - Manuals

Indicates that there is a 3 k X pull-up resistor on these outputs when theyare disabled. TL/F/5012 – 1 FIGURE 1. DP8409A Block Diagram TABLE II. DP8409A Mode Select Options Mode (RFSH) M1 M0 Mode of Operation Conditions M2 0 0 0 0 Externally Controlled Refresh RF I/O e EOC 1 0 0 1 Auto RefreshÐForce...

Refreshing The DP8409A also provdes hidden refresh capability whilein one of the automatic access modes ( Figure 4 ). In this mode, it will automatically perform a refresh without the sys-tem being interrupted. To do this, the DP8409A requires twoclock signals, refresh clock (RFCK) which defines the...

TABLE IV. Check Bit Overhead for Multiple Bit Error Detection and Single Bit Error Correction Number of Bits Number of Percentage in Memory Check Bits of Excess Data Word Required Memory 8 5 63% 16 6 38% 24 6 (7) 25% (29%) 32 7 22% 48 7 (8) 15% (17%) 64 8 13% Note: The number stated assumes the use ...