Hello, Many people write that it is quite easy to add additional peripherals to the T51 core by means of the SFR bus. Are there any VHDL examples out there on the net? =) Reason why I am asking: I want to extend/modify the T51 IP core to make the 8052 into a 100% compatible NXP 80C522 microcontroller. As you might know, this means: 1) I2C, 2) Compare registers, 3) PWM, etc. The extended T51 should be 100% compatible with the 80C522, meaning that the original ROM code should run flawless. Adding a peripheral to the SFR bus might be easy, but if so, how come that there are no concrete VHDL examples for the T51 IP core in particular. Additional question: If you add a peripheral by means of Wishbone, does the microcontroller code need to know about the peripheral bus, or would it work in similar way as if it was connected to the Intel SFR bus? It looks like using the Wishbone bus, would mean customer microcontroller code, therefore I prefer to stick with the original SFR bus, as that was designed exactly for the purpose to have a common 8051 core, and extend the core to its own flavour while staying compatible... But again.. then I would like to have some example. Is there anybody out there who did a similar project like the one I suggested.. e.g. converting T51 8052 into a 80C522 microcontroller IP core =) BTW. It's totally okey to write back in German if that is easier for you. I do understand german. Thanks for your help, /Pascal
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I have made similar things in past. My base was a 8031 verilog source, that i converted to 8032 source, and then extended to the needed peripherials. The project required the same timing as the orginal chip. I doubt, that with the T51 implementation you will be 100% compatible with the orginal chip and timing cycles.
Hello, The most important thing is code compatibility. Timing less important. Did you add the peripherals by means of the SFR bus? Any examples left? or do you have some good application note/reference document/tutorial to add peripherals to the SFR bus? Any help appreciated! Thanks, /Pascal
Hi, because i don´t have used the T51 branch, i could not helping with it. I have some examples of adding I2C and PWM to the 8051 from the University of California if this could help, but it don´t help if you want use the T51. Regards Chris
Hello, Thanks for your feedback. Does the Dalton 8051 support SFR bus or did you add peripherals in different way to the main core? Thanks, /Pascal
Usually, if the core have a dedicated SRF bus, then you must make a write decoder and a read multiplexer for accessing the user supplied periferial extension. This components are not needed, if the core is used without user extension. Maybe this is the info you miss. Further, depending on the implementation, there may be different signals for the bus read cycle, if the operation is read only or read-modify-write.
Hello, About the examples for adding I2C and PWM to the Dalton 8051. Can you provide this code? I want to add similar to the Open Cores T52: 8052. Thanks, /Pascal