U630H16P

The U630H16P has two separate modes of operation: SRAM mode and nonvolatile mode, determined by the state of the NE pin.

In SRAM mode, the memory U630H16P operates as an ordinary static RAM. Innonvolatile operation, data is transferred in parallel from SRAM to EEPROM or from EEPROM to SRAM. In this mode SRAM functions are disabled.

The U630H16P is a fast static RAM (35 ns), with a nonvolatile electrically erasable PROM (EEPROM) element incorporated in each static memory cell. The SRAM U630H16P can be read and written an unlimited number of times, while independent nonvolatile data resides in EEPROM. Data transfers from the SRAM to the EEPROM (the STORE operation), or from the EEPROM to the SRAM (the RECALL operation) are initiated through the state of the NE pin or through software sequences.

The U630H16P combines the high performance and ease of use of a fast SRAM with nonvolatile data integrity.

Once a STORE cycle U630H16P is initiated, further input or output are disabled until the cycle is completed.

Because a sequence of addresses is used for STORE U630H16P initiation, it is important that no other read or write accesses intervene in the sequence or the sequence will be aborted.

Internally, RECALL U630H16P is a two step procedure. First, the SRAM data is cleared and second, the nonvolatile information is transferred into the SRAM cells.

The RECALL U630H16P operation in no way alters the data in the EEPROM cells. The nonvolatile data can be recalled an unlimited number of times.