| ??? 12/19/07 07:58 Read: times |
#148495 - T89C51CC01UA not run on external code memory (2) Responding to: ???'s previous message |
I had successfuly use FM0 - Flash memory user spaces to start an application that can read the external ROM, read/write external RAM and control and T6963 based LCD display. But I can not make the same program run inside the external ROM - even the program is just few instructions to toggle an LED.
Even an P87C591 with internal flash, it is just simply tie EA to 0V and program must fetch from external memory. The external flash is AT29C010A-90, crystal is 20MHz. I checked: - PSEN and ALE signal correct. AT29C010A OE is connected to PSEN and RD through HC08. - Same problems when X2 set or clear by FLIP2.4. - HC139 and HC573 are used as address decoding and chip selection (Program running in internal flash FM0 do not have problems, is there any chance hardware incorrect?) - Remove the RAM and LCD display, simply blinking and LED connected to P3.4. Program work inside internal flash FM0 but not for external ROM. - Because AT29C010A is 256k, two address line A16 & A17 are connected to two port line P3.2 and P3.3. I know this so I copy the program bin file to address 0x00000, 0x10000, 0x20000 and 0x30000. P3.2 and P3.3 are both high after reset and program must be start at "0x30000". Anyone know this and fixed? |
| Topic | Author | Date |
| T89C51CC01UA not run on external code mem | 01/01/70 00:00 | |
| T89C51CC01UA not run on external code memory (2) | 01/01/70 00:00 | |
| I see no mention of !EA | 01/01/70 00:00 | |
| Re: I see no mention of !EA | 01/01/70 00:00 | |
| clock and ALE | 01/01/70 00:00 | |
| Re: clock and ALE | 01/01/70 00:00 | |
| Re: clock and ALE | 01/01/70 00:00 | |
| hardware security byte | 01/01/70 00:00 | |
| not an admonsihment, just a thought | 01/01/70 00:00 | |
Re: hardware security byte | 01/01/70 00:00 | |
| T89C51CC01UA not run on external code mem | 01/01/70 00:00 |