Hello all, I am using an HC11EVBU2 board with an HC11E9 chip on it, and it also appears to have some external memory on the board as well. I'm trying to find room to write code in where I won't overwrite anything important or have to write to the EPROM (I'm trying to take one step at a time here). In Single Chip Mode I've determined that I can write code in RAM in area 0000-0035 and 0100-01FF and in EEPROM from B600-B7FF for a total of 812 bytes of usable space. (I'm using the Buffalo Monitor since I havn't been able to get the Bootstrap Mode to work correctly so far) In Expanded Mode it seems that I can also write to the areas before and after the EEPROM, 8000-B5FF and B800-CFFF. So, couple of questions here. -What exatly are these areas, are they both External RAM? -Since I don't want to accidetally overwrite the BUFFALO program, where exactly is it located? -In the Bootstrap and Special Test modes the areas BF00-BFBF and BFC0-BFFF are set aside for the Boot Rom and Special Mode Interrupt Vectors, respectively. Should these areas not be written to in order to not over-write that information? Also, my understanding is that even if I can write to these area in Expanded Mode that I can't read from them in single-chip mode because they use ports b and c for address and data information (which I'm going to need for I/O), is this correct? Basically it seems to me that in order to be able to utilize more than the 812 bytes of RAM & EEPROM I'm going to have to modify the board to be able to program the EPROM. Any clarification would be greatly appreciated. -R.DG
68HC11E9 - Usable Memory for Programming?
Started by ●March 17, 2006
Reply by ●March 17, 20062006-03-17
I cannot answer all your questions, but see below for what I can answer. Emmett Redd Ph.D. mailto:EmmettRedd@Emme... Associate Professor (417)836-5221 Department of Physics, Astronomy, and Materials Science Missouri State University Fax (417)836-6226 901 SOUTH NATIONAL Dept (417)836-5131 SPRINGFIELD, MO 65897 USA "When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things," like being too embarrassed to ask questions which my peers might think as stupid. > -----Original Message----- > From: m68HC11@m68H... > [mailto:m68HC11@m68H...] On Behalf Of celeritas_scientia > Sent: Friday, March 17, 2006 12:40 PM > To: m68HC11@m68H... > Subject: [m68HC11] 68HC11E9 - Usable Memory for Programming? > > Hello all, > > I am using an HC11EVBU2 board with an HC11E9 chip on it, and it also > appears to have some external memory on the board as well. I'm trying > to find room to write code in where I won't overwrite anything > important or have to write to the EPROM (I'm trying to take one step > at a time here). > > In Single Chip Mode I've determined that I can write code in RAM in > area 0000-0035 and 0100-01FF and in EEPROM from B600-B7FF for a total > of 812 bytes of usable space. (I'm using the Buffalo Monitor since I > havn't been able to get the Bootstrap Mode to work correctly so far) > > In Expanded Mode it seems that I can also write to the areas before > and after the EEPROM, 8000-B5FF and B800-CFFF. So, couple of questions > here. > > -What exatly are these areas, are they both External RAM? Although I have no experience with the EVBU2, I would expect the areas are external RAM. Don't you have any documentation on your board to tell you? Myself, I would just try to store something there. > > -Since I don't want to accidetally overwrite the BUFFALO program, > where exactly is it located? BUFFALO starts at $E000 and ends at $FFFF. There may be some unused locations. But they cannot be changed because they are ROM. In fact, since your chip is not a 68HC711E9, you cannot change any of the ROM including BUFFALO contained within it. > > -In the Bootstrap and Special Test modes the areas BF00-BFBF and > BFC0-BFFF are set aside for the Boot Rom and Special Mode Interrupt > Vectors, respectively. Should these areas not be written to in order > to not over-write that information? They are not in the memory map in Normal modes. Therefore, you cannot write to them. BTW, they are ROM; you cannot write to them in the Special Modes either. > > Also, my understanding is that even if I can write to these area in > Expanded Mode that I can't read from them in single-chip mode because > they use ports b and c for address and data information (which I'm > going to need for I/O), is this correct? Basically it seems to me that > in order to be able to utilize more than the 812 bytes of RAM & EEPROM > I'm going to have to modify the board to be able to program the EPROM. You could add a Port Replacement Unit (PRU). I don't have any documentation that tell you more right now. Check out the archived messages. There are several messages/threads about the PRU. Where is your EPROM (physically and in the memory map)? > > Any clarification would be greatly appreciated. > > -R.DG >
Reply by ●March 19, 20062006-03-19
Here, try this. You will indeed be unable to use Ports B & C while
in
expanded mode...and if you use single chip mode, the amount of memory
storage is pitiful. If you look back at some of my email to the group you
can see I was having similar problems...I wound up using expanded mode (so
no Ports B & C), but if you have the Axiom (CME) board, this loss is
somewhat compensated by the use ot the BUS_PORT, and LCD_PORT, both of which
offer I/O by writing to dedicated memory locations at $B580-B5ff....see my
message about "being my own answer" in this YahooGroup.
You can also try the Port Replacement Unit from Tekmos, but if you have
the Axiom board, you're going to have to troubleshoot (and possibly run a
jumper wire for) the RESET pin. TJ
>From: "celeritas_scientia"
<Sakkar99@Sakk...>
>Reply-To: m68HC11@m68H...
>To: m68HC11@m68H...
>Subject: [m68HC11] 68HC11E9 - Usable Memory for Programming?
>Date: Fri, 17 Mar 2006 18:39:38 -0000
>
>
>
>
>
>Hello all,
>
>
>
>I am using an HC11EVBU2 board with an HC11E9 chip on it, and it also
>
>appears to have some external memory on the board as well. I'm trying
>
>to find room to write code in where I won't overwrite anything
>
>important or have to write to the EPROM (I'm trying to take one step
>
>at a time here).
>
>
>
>In Single Chip Mode I've determined that I can write code in RAM in
>
>area 0000-0035 and 0100-01FF and in EEPROM from B600-B7FF for a total
>
>of 812 bytes of usable space. (I'm using the Buffalo Monitor since I
>
>havn't been able to get the Bootstrap Mode to work correctly so far)
>
>
>
>In Expanded Mode it seems that I can also write to the areas before
>
>and after the EEPROM, 8000-B5FF and B800-CFFF. So, couple of questions
>
>here.
>
>
>
>-What exatly are these areas, are they both External RAM?
>
>
>
>-Since I don't want to accidetally overwrite the BUFFALO program,
>
>where exactly is it located?
>
>
>
>-In the Bootstrap and Special Test modes the areas BF00-BFBF and
>
>BFC0-BFFF are set aside for the Boot Rom and Special Mode Interrupt
>
>Vectors, respectively. Should these areas not be written to in order
>
>to not over-write that information?
>
>
>
>Also, my understanding is that even if I can write to these area in
>
>Expanded Mode that I can't read from them in single-chip mode because
>
>they use ports b and c for address and data information (which I'm
>
>going to need for I/O), is this correct? Basically it seems to me that
>
>in order to be able to utilize more than the 812 bytes of RAM & EEPROM
>
>I'm going to have to modify the board to be able to program the EPROM.
>
>
>
>Any clarification would be greatly appreciated.
>
>
>
>-R.DG
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
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Reply by ●March 20, 20062006-03-20
The EVBU unit is factory configured for single chip mode, for expanded mode you need to cut the J4 cut-trace short. $0000-$0047 and $0100-$01FF are on-chip RAM available to user BUFFALO uses the MCU on-chip RAM from $0048-00FF. and is located in the internal ROM. You may use BUFFALO to program the EEPROM for user program code. Switching jumper J2 to pin 1 & 2 (default is pin 2 & 3), upon reset it automatically jumps directly to location $B600. Hope this helps, regards. -----Original Message----- From: m68HC11@m68H... [mailto:m68HC11@m68H...]On Behalf Of Redd, Emmett R Sent: Saturday, March 18, 2006 3:19 AM To: m68HC11@m68H... Subject: RE: [m68HC11] 68HC11E9 - Usable Memory for Programming? I cannot answer all your questions, but see below for what I can answer. Emmett Redd Ph.D. mailto:EmmettRedd@Emme... Associate Professor (417)836-5221 Department of Physics, Astronomy, and Materials Science Missouri State University Fax (417)836-6226 901 SOUTH NATIONAL Dept (417)836-5131 SPRINGFIELD, MO 65897 USA "When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things," like being too embarrassed to ask questions which my peers might think as stupid. > -----Original Message----- > From: m68HC11@m68H... > [mailto:m68HC11@m68H...] On Behalf Of celeritas_scientia > Sent: Friday, March 17, 2006 12:40 PM > To: m68HC11@m68H... > Subject: [m68HC11] 68HC11E9 - Usable Memory for Programming? > > Hello all, > > I am using an HC11EVBU2 board with an HC11E9 chip on it, and it also > appears to have some external memory on the board as well. I'm trying > to find room to write code in where I won't overwrite anything > important or have to write to the EPROM (I'm trying to take one step > at a time here). > > In Single Chip Mode I've determined that I can write code in RAM in > area 0000-0035 and 0100-01FF and in EEPROM from B600-B7FF for a total > of 812 bytes of usable space. (I'm using the Buffalo Monitor since I > havn't been able to get the Bootstrap Mode to work correctly so far) > > In Expanded Mode it seems that I can also write to the areas before > and after the EEPROM, 8000-B5FF and B800-CFFF. So, couple of questions > here. > > -What exatly are these areas, are they both External RAM? Although I have no experience with the EVBU2, I would expect the areas are external RAM. Don't you have any documentation on your board to tell you? Myself, I would just try to store something there. > > -Since I don't want to accidetally overwrite the BUFFALO program, > where exactly is it located? BUFFALO starts at $E000 and ends at $FFFF. There may be some unused locations. But they cannot be changed because they are ROM. In fact, since your chip is not a 68HC711E9, you cannot change any of the ROM including BUFFALO contained within it. > > -In the Bootstrap and Special Test modes the areas BF00-BFBF and > BFC0-BFFF are set aside for the Boot Rom and Special Mode Interrupt > Vectors, respectively. Should these areas not be written to in order > to not over-write that information? They are not in the memory map in Normal modes. Therefore, you cannot write to them. BTW, they are ROM; you cannot write to them in the Special Modes either. > > Also, my understanding is that even if I can write to these area in > Expanded Mode that I can't read from them in single-chip mode because > they use ports b and c for address and data information (which I'm > going to need for I/O), is this correct? Basically it seems to me that > in order to be able to utilize more than the 812 bytes of RAM & EEPROM > I'm going to have to modify the board to be able to program the EPROM. You could add a Port Replacement Unit (PRU). I don't have any documentation that tell you more right now. Check out the archived messages. There are several messages/threads about the PRU. Where is your EPROM (physically and in the memory map)? > > Any clarification would be greatly appreciated. > > -R.DG > Yahoo! Groups Links
