The AT29C432 is a CMOS memory specifically designed for applications requiring both a high density nonvolatile program memory and a smaller nonvolatile data memory. The AT29C432 provides this in the form of a 4 megabit Flash array integrated with a 256K bit full featured E2PROM array on the same device. A unique feature of this device is its concurrent read while writing capability. This provides the host system read access to the Flash program memory during the write cycle time of the E2PROM.