The Turbo IC 29C021 is a 256K x 8 Flash programmable and erasable read only memory (PEROM) fabricated with Turbo IC's proprietary, high reliability, high performance CMOS technology. Its 2048K bits of memory are organized as 256K by 8 bits. The device offers access time of 150 ns with power dissipation below 330 mW. The 29C021 has a 128 bytes sector program operation enabling the entire memory to be programmed typically in less than 21 seconds. During a program operation, the address and a complete sector (128 bytes) of data are internally latched, freeing the address and data bus for other microprocessor operations. The programming process is automatically controlled by the device using an internal control timer. Data polling on I/O7 or a Toggle bit can be used to detect the end of a programming cycle. In addition, the 29C021 includes an user-optional software data write mode offering additional protection against unwanted (false) write. The 29C021 does not require a separate high voltage to program the device. 5 volts is all that is required.