READ ONLY MEMORY PACKAGE WITH WRITING FUNCTION

摘要

PURPOSE:To obtain a read-only memory ROM package having a writing function by using plural ROM chips, an external connector, an address bus, a data bus, a chip selection signal line, and a data reading signal line. CONSTITUTION:The data are not written into ROM chips 4a and 4b yet. A chip selection signal line 5a and a data writing signal line 6a are set in the enable state by a data bus 2 via an external connector 7. Then an address is sent to an address bus 1, and the write data is sent to the bus 2 and written into the chip 4a. Thus both signal lines 5b and 6b are set in the enable state, and the data is written into the chip 4b. Thus a ROM package is completed. A data reading signal line 3 and the line 5a of the ROM to be read out are set in the enable state via the connector 7 and an address is given to the bus 1. Thus the data is sent to the bus 2 from the desired ROM and can be read via the connector 7. In such a constitution, a ROM package containing a writing function is obtained.