AT27C256R-70PU Datasheet, PDF (5/14 Pages) ATMEL Corporation – 256K (32K x 8) One-time Programmable, Read-only Memory

Figure 5-1. AC waveforms for read operation⁽¹⁾
Atmel AT27C256R
Notes:
1. Timing measurement reference level is 1.5V for -45 devices. Input AC drive levels are V_IL = 0.0V and V_IH = 3.0V. Timing
measurement reference levels for all other speed grades are V_OL = 0.8V and V_OH = 2.0V. Input AC drive levels are V_IL =
0.45V and V_IH = 2.4V.
2. OE may be delayed up to t_CE - t_OE after the falling edge of CE without impact on t_CE.
3. OE may be delayed up to t_ACC - t_OE after the address is valid without impact on t_ACC.
4. This parameter is only sampled, and is not 100% tested.
5. Output float is defined as the point when data is no longer driven.
Figure 5-2. Input test waveforms and measurement levels
For -45 devices only:
t_R, t_F < 5ns (10% to 90%)
For -70 devices:
t_R, t_F < 20ns (10% to 90%)
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