The Microchip Technology Inc. 28C04A is a CMOS 4K
non-volatile electrically Erasable and Programmable
Read Only Memory (EEPROM). The 28C04A is
accessed like a static RAM for the read or write cycles
without the need of external components. During a
“byte write”, the address and data are latched internally,
freeing the microprocessor address and data bus
for other operations. Following the initiation of write
cycle, the device will go to a busy state and automatically
clear and write the latched data using an internal
control timer. To determine when a write cycle is complete,
the 28C04A uses Data polling. Data polling
allows the user to read the location last written to when
the write operation is complete. CMOS design and processing
enables this part to be used in systems where
reduced power consumption and reliability are
required. A complete family of packages is offered to
provide the utmost flexibility in applications.