Semiconductor memory device

摘要

The invention provides a semiconductor memory device which can easily constitute a large-capacity memory system for a compact information terminal at low cost. The semiconductor memory device (RAM) which receives a command from a CPU to read and write data is connected to a storage flash memory for reading and writing data in predetermined access units. The RAM includes a flash interface circuit for generating a control signal required for data access to the flash memory in synchronism with the command from the CPU, and a pseudo-SRAM serving as a memory element which can be randomly accessed. The RAM reads/writes data from/to either the flash memory or the pseudo-SRAM in accordance with the commands from the CPU.