View source for Unknown Year, 5.2L MC68HC16Z2 Initialization Code Overview

* Reset Vector = 0x0
First byte of reset vector = PK (Program Counter Extension)

Second byte of reset vector = SK (Stack Pointer Extension)

Third byte of reset vector = ZK (Index Z Extension)

PK = 0x01

SK = 0xFF

ZK = 0xFF


Initial PC = 0x0 | PK = (0x10000)


* 0x10000 Jump to 0x20000

* 0x20002 Wrote 0xFF to SK

* 0x20004 Wrote 0xFF to ZK

* 0x20006 Wrote 0xF8FE to SP

* 0x2000A Wrote 0xF800 to Z

* 0x20010 Wrote 0x00 to EK, XK, & YK 

* 0x2001E Write 0xB4 to SYPCR

  Enabled Watchdog

  Turned off scaling

  Set timeout to 2 to the 15th


* 0x20024 Wrote 0x55 to SWSR

* 0x2002A Wrote 0xAA to SWSR

  Writing 0x55 then 0xAA to SWSR pets the watchdog