| Part Numbert | Mfg | Packt | D/C | Descriptiont | Qty | Company/Contact |
PC74HCT273T.652 PC74HCT273T.652 PC74HCT273T652 Datasheet
PC74HCT273T.652 PC74HCT273T.652 PC74HCT273T652 Price The software protection scheme can be enabled by apply- ing a three-byte sequence to the device, during a page- load cycle (Figures 5 and 6). The device will then be auto- matically set into the data protect mode. Any subsequent Write operation will require the preceding three-byte sequence. See Table 4 for the specific software command codes and Figures 5 and 6 for the timing diagrams. To set the device into the unprotected mode, a six-byte sequence is required. See Table 4 for the specific codes and Figure 9 for the timing diagram. If a write is attempted while SDP is enabled the device will be in a non-accessible state for ~300ps. SST recommends Software Data Protection always be enabled. See Figure 17 for flowcharts. PC74HCT273T.652 PC74HCT273T.652 PC74HCT273T652 on stock
NOTES: 1. All of the SDRAM operations are defined by states of SDCEV SDWEV SDRASV SDCASV and BWE0-3 at the positive rising edge of the clock. 2. Bank Select (BA), if A12 (BAo) and A13 (BAi) select between different banks. 3. During a Burst Write cycle there is a zero clock delay, for a Burst Read cycle the delay is equal to the CAS latency. 4. The BWE has two functions for the data DQ Read and Write operations. During a Read cycle, when BWE goes high at a clock timing the data outputs are disabled and become high impedance after a two clock delay. BWE also provides a data mask function for Write cycles. When it activates, the Write operation at the clock is prohibited (zero clock latency). |
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