EPROM/OTPROM Module MTT48 V EPROM PROGRAMMING

EPROM/OTPROM Module MTT48 V Module Objective Learn the difference between EPROM and OTPROM. Learn how to program the EPROM.

EPROM/OTPROM Module MTT48 V EPROM MODULE 68HC08 CPU System Integration Module (SIM) Clock Generation Module (CGM) Timer Interface Module (TIM) Direct Memory Access Module (DMA) Serial Communications Interface (SCI) Internal Bus (IBUS) Serial Peripheral Interface (SPI) Random Access Memory (RAM) Electronically Programmable Memory (EPROM) LVI COP Monitor ROM IRQ BREAK RESET EPROM Erasable, 36 Kbytes ProgrammableOTPROM One-Time, 36 Kbytes Programmable ROM MCU without the quartz window can’t be erased EPROM/OTPROM Memory Locations: $6E00 -$FDFF

EPROM/OTPROM Module MTT48 V EPROM/OTPROM Control Register EPROM Control Register (EPMCR) EPROM/OTPROM Charge Pump Disable (EPMCPD) –Used for reading EPROM at low voltage –Disable pump if MCU is operating at 2.7 V or higher 1 = Charge pump disabled 0 = Charge pump enabled EPROM/OTPROM Latch Control (ELAT) –Latches the address and data buses for programming 1 = Buses set for EPROM/OTPROM programming 0 = Buses set for normal operation –Clearing ELAT also clears the program control bit(EPGM) –Data cannot be read when ELAT is set EPROM/OTPROM Program Control (EPGM) –Applies IRQ1/V PP voltage to EPROM/OTPROM –ELAT must already be set to write to EPGM 1 = EPROM/OTPROM programming power switched on 0 = EPROM/OTPROM programming power swithced off READ: RESET: WRITE: EPMCR $FE07 EPMCPD ELAT EPGM

EPROM/OTPROM Module MTT48 V EPROM/OTPROM Programming Sequence Sequence for programming a byte of EPROM/OTPROM: 1) Apply the programming voltage to IRQ1/V PP pin 2) Set the ELAT bit 3) Write to any EPROM/OTPROM address –Note: writing to an invalid address prevents the programming voltage from being applied. 4) Set the EPGM bit 5) Wait for a time, t EPGM. 6) Clear the ELAT and EPGM bits note - Clearing the ELAT bit automatically clears the EPGM –Setting the ELAT and EPGM bit with one instruction will set ELAT but clear EPGM. –EPGM must be set by a separate instruction in the programming sequemce.

EPROM/OTPROM Module MTT48 V Security Mask Option Register (MOR) EPROM/OTPROM Security bit (SEC) –Prevents reading of the EPROM/OTPROM –Writing to the MOR register has no effect 1 = EPROM/OTPROM security enabled 0 = EPROM/OTPROM security disabled RESET: UNAFFECTED BY RESET WRITE: MOR READ: 0 LVISTOP LVIRST LVIPWR SSREC SEC STOP COPD

EPROM/OTPROM Module MTT48 V Low Power STOP mode Charge pump returns to V DD Exiting STOP mode Charge pump resumes/stabilizes during oscillator start up

EPROM/OTPROM Module MTT48 V Summary RESET: UNAFFECTED BY RESET WRITE: MOR READ: 0 LVISTOP LVIRST LVIPWR SSREC SEC STOP COPD READ: RESET: WRITE: EPMCR $FE07 EPMCPD ELAT EPGM