MC68HC05B6_13 Datasheet, PDF (219/302 Pages) Freescale Semiconductor, Inc – Microcontrollers

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MC68HC705B16N
The MC68HC705B16N is a new device identical to the MC68HC705B16 in its memory
map and functionality, except for the following:
• Bootloader
• Reset pulse width
• Reset twice issue
• Electrical characteristics
On the MC68HC705B16 there was a requirement to reset the device a second time
after power-on. On the MC68HC705B16N this reset twice action is now not required.
The interrupt service routine for the vector at address $3FF0–$3FF1 is no longer
required, as the vector will never be fetched. However, the interrupt service routine and
vector contents required for the MC68HC705B16 (see Section E, page E–1) can also
be kept on the MC68HC705B16N with no detrimental effect, although they will never
be used.
The MC68HC705B16N is a device similar to the MC68HC05B6, but with increased RAM and
15 kbytes of EPROM instead of 6 kbytes of ROM. In addition, the self-check routines available in
the MC68HC05B6 are replaced by bootstrap firmware. The MC68HC705B16N is an OTPROM
(one-time programmable ROM) version of the MC68HC05B16, meaning that once the application
program has been loaded in the EPROM it can never be erased. The entire MC68HC05B6 data
sheet applies to the MC68HC705B16N, with the exceptions outlined in this appendix.
MC68HC05B6
Rev. 4.1
MC68HC705B16N
14
Freescale
F-1