Freescale Semiconductor, Inc.
EPROM/OTPROM
EPROM Registers
Whenever the ELAT bit is cleared, the EPGM bit is also cleared. Both
the EPGM and the ELAT bit cannot be set using the same write
instruction. Any attempt to set both the ELAT and EPGM bit on the same
write instruction cycle will result in the ELAT bit being set and the EPGM
bit being cleared. To program a byte of EPROM, manipulate the EPROG
register as follows:
1. Set the ELAT bit in the EPROG register.
2. Write the desired data to the desired EPROM address.
3. Set the EPGM bit in the EPROG register for the specified
programming time, t
.
EPGM
4. Clear the ELAT and EPGM bits in the EPROG register.
13.3.2 Ma sk Op tion Re g iste r (MOR)
The mask option register (MOR) shown in Figure 13-2 is an EPROM
byte that controls eight mask options. The MOR is unaffected by reset.
The erased state of the MOR is $00. The options that can be
programmed by the MOR are:
1. Port software programmable pulldown devices (enable or disable)
2. Startup delay after stop (16 or 4064 cycles)
3. Oscillator shunt resistor (2 M or open)
4. STOP instruction (enable or disable)
5. Low-voltage reset (enable or disable)
6. Port A external interrupt function (enable or disable)
7. IRQ trigger sensitivity (edge-triggered only or both edge- and
level-triggered)
8. COP watchdog (enable or disable)
MC68HC705JJ7/MC68HC705JP7 — Rev. 3.0
General Release Specification
EPROM/OTPROM
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