M16C/62 Group DATASHEET

CPU Rewrite Mode (Flash Memory Version)Mitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTERPage Program Command (4116)Page program allows for high-speed programming in units of 256 bytes. Page program operationstarts when the command code “4116” is written in the first bus cycle. In the second bus cycle throughthe 129th bus cycle, the write data is sequentially written 16 bits at a time. At this time, the addressesA0-A7 need to be incremented by 2 from “0016” to “FE16.” When the system finishes loading the data,it starts an auto write operation (data program and verify operation).Whether the auto write operation is completed can be confirmed by reading the status register or theflash memory control register 0. At the same time the auto write operation starts, the read statusregister mode is automatically entered, so the content of the status register can be read out. Thestatus register bit 7 (SR7) is set to 0 at the same time the auto write operation starts and is returned to1 upon completion of the auto write operation. In this case, the read status register mode remainsactive until the Read Array command (FF16) or Read Lock Bit Status command (7116) is written or theflash memory is reset using its reset bit.____The RY/BY status flag of the flash memory control register 0 is 0 during auto write operation and 1when the auto write operation is completed as is the status register bit 7.After the auto write operation is completed, the status register can be read out to know the result of theauto write operation. For details, refer to the section where the status register is detailed.Figure 1.29.4 shows an example of a page program flowchart.Each block of the flash memory can be write protected by using a lock bit. For details, refer to thesection where the data protect function is detailed.Additional writes to the already programmed pages are prohibited.StartWrite 4116n = 0Write address n anddata nn = n + 2n = FE16NOYESRY/BY status flag= 1?NOYESCheck full statusPage programcompletedFigure 1.29.4. Page program flowchart242