MCMC68HC05L16 Freescale Semiconductor, Inc, MCMC68HC05L16 Datasheet - Page 137

• Manufacturer Part Number: MCMC68HC05L16
• Description: M68hc05 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

A.9 Boot ROM
Boot ROM is 496 bytes of mask ROM positioned at $FE00–$FFEF. This ROM contains bootstrap loader
programs and reset/interrupt vectors in the bootstrap mode. The bootstrap loader programs include:
A.10 EPROM
The 16-Kbyte EPROM is positioned at $1000–$4FFF, and the additional 16 bytes of EPROM are located
at $FFF0–$FFFF for user vectors. The erased state of EPROM is read as $FF and EPROM power is
supplied from the V
The program control register (PCR) is provided for EPROM programming and testing. The functions of
EPROM depend on the device mode.
In user mode, ELAT and PGM bits in the PCR are available for user programming, and the remaining test
bits become read-only bits. The V
A.10.1 Programming Sequence
To program the MC68HC705L16, execute this sequence:
Clearing the PGM bit and the ELAT bit may be done on a single CPU write.
Freescale Semiconductor
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EPROM programming and verification
Dumping EPROM contents
Loading programs into the internal RAM
Executing programs in the internal RAM
Set the ELAT bit
Write the data to the address to be programmed
Set the PGM bit
Delay for an appropriate amount of time
Clear the PGM bit and the ELAT bit
It is important to remember that an external programming voltage must be
applied to the V
during normal operations.
PP
pin and the V
MC68HC05L16 • MC68HC705L16 Data Sheet, Rev. 4.1
PP
pin while programming, but it should be equal to V
PP
DD
pin should be tied to 5 volts or programming voltage.
pin.
NOTE
DD
Boot ROM
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