9

2321I–CNFG–2/08

AT17LV65/128/256/512/010/002/040

7.

Cascading Serial Configuration EEPROMs

For multiple FPGAs configured as a daisy-chain, or for FPGAs requiring larger configuration

memories, cascaded configurators provide additional memory.

After the last bit from the first configurator is read, the clock signal to the configurator asserts its

CEO output Low and disables its DATA line driver. The second configurator recognizes the Low

level on its CE input and enables its DATA output.

After configuration is complete, the address counters of all cascaded configurators are reset if

the RESET/OE on each configurator is driven to its active (Low) level.

If the address counters are not to be reset upon completion, then the RESET/OE input can be

tied to its inactive (High) level.

The AT17LV65 devices do not have the CEO feature to perform cascaded configurations.

8.

AT17LV Series Reset Polarity

The AT17LV series configurator allows the user to program the reset polarity as either

RESET/OE or RESET/OE. This feature is supported by industry-standard programmer

algorithms.

9.

Programming Mode

The programming mode is entered by bringing SER_EN Low. In this mode the chip can be pro-

grammed by the Two-Wire serial bus. The programming is done at V

Programming super voltages are generated inside the chip.

10. Standby Mode

The AT17LV series configurators enter a low-power standby mode whenever CE is asserted

High. In this mode, the AT17LV65/128/256 configurator consumes less than 50 µA of current at

3.3V (100 µA for the AT17LV512/010 and 200 µA for the AT17LV002/040). The output remains

in a high-impedance state regardless of the state of the OE input.