M16C/62 Group DATASHEET

Usage precautionMitsubishi microcomputersM16C / 62 GroupSINGLE-CHIP 16-BIT CMOS MICROCOMPUTERExternal ROM versionThe external ROM version is operated only in microprocessor mode, so be sure to perform the following:• Connect CNVss pin to Vcc.• Fix the processor mode bit to “112”Built-in PROM version(1) All built-in PROM versionsHigh voltage is required to program to the built-in PROM. Be careful not to apply excessive voltage.Be especially careful during power-on.(2) One Time PROM versionOne Time PROM versions shipped in blank (M30620ECFP, M30620ECGP), of which built-in PROMsare programmed by users, are also provided. For these microcomputers, a programming test andscreening are not performed in the assembly process and the following processes. Therefore ROMwrite defectiveness occurs around 5 %. To improve their reliability after programming, we recommendto program and test as flow shown in Figure 1.24.1 before use.Programming with PROM programmerScreening (Note)(Leave at 150˚C for 40 hours)Verify test PROM programmerFunction check in target deviceNote: Never expose to 150˚C exceeding 100 hours.Figure 1.24.1. Programming and test flow for One Time PROM version(3) EPROM version• Cover the transparent glass window with a shield or others during the read mode because exposingto sun light or fluorescent lamp can cause erasing the information.A shield to cover the transparent window is available from Mitsubishi Electric Corp. Be careful thatthe shield does not touch the EPROM lead pins.• Clean the transparent glass before erasing. Fingers’ flat and paste disturb the passage of ultravioletrays and may affect badly the erasure capability.• The EPROM version is a tool only for program development (for evaluation), and do not use it for themass product run.179