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I'm working with the MC912D60A microcontroller. I just realized the
access for EEPROM earasing and programming. So far everything works fine. It's just that I don't understand the idea of the SHADOW byte. Form the specs I read it is located at adress 0x0FC0- 0x0FC1. Actually these are adresses where my RAM is located (0x0800-0x0FFF). I moved my EEPROM area to adress 0x1C00-0x1FFF. Does this means my shadow registers are also moved to 0x1FC0 - 0x1FC1 ? What happens if I ignore the shadow registers? Is there more stress for the eeprom array (maybe in debbuging mode)? Thanks for further help... Hansi Schlhorn |
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EEPROM Shadow Byte
Started by ●May 23, 2002
Reply by ●May 28, 20022002-05-28
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Hansi, The shadow row will move with the rest of the EEPROM, so the shadow row will be located at 0x1FC0 as you've presumed. The shadow row is normally not visible, but when enabled (writing a 0 to the NOSHB bit in the EEMCR when in one of the special modes) it overlays the 'normal' EEPROM. Unless you want to enable the BDM lock out feature in the MC68HC912D60(A) or the MC68HC912DG/DA/DT128(A) parts, you can ignore the existence of the shadow row. Regards, Gordon "Schlhorn, Hanspeter" wrote: > I'm working with the MC912D60A microcontroller. I just realized the access > for EEPROM earasing and programming. So far everything works fine. It's just > that I don't understand the idea of the SHADOW byte. Form the specs I read > it is located at adress 0x0FC0- 0x0FC1. > Actually these are adresses where my RAM is located (0x0800-0x0FFF). I moved > my EEPROM area to adress 0x1C00-0x1FFF. > Does this means my shadow registers are also moved to 0x1FC0 - 0x1FC1 ? > What happens if I ignore the shadow registers? Is there more stress for the > eeprom array (maybe in debbuging mode)? > > Thanks for further help... > > Hansi Schlhorn > -------------------- > > ">http://docs.yahoo.com/info/terms/ -- =============================================================== Gordon Doughman Ph: 937-438-6811 Motorola Semiconductor Fax: 937-434-7457 Field Applications Engineer Pager: 800-759-8352 Pin: 1304089 Suite 175 3131 Newmark Drive Miamisburg, OH 45342 Check out my HC12 book at: http://www.annatechnology.com/annatech/bookBrowseByMicroF.asp |
