??? 09/11/11 22:22 Read: times |
#183711 - For Software Controlled Strobing... Responding to: ???'s previous message |
Erik Malund said:
In particular when the microcontroller is a SiLabs type the I/Os can be set to push-pull and the communications to the display works well. fine, if you do not need bi-directional comms, which I have always needed.
If you are using software controlled strobing to a peripheral and the MCU is the single master controller you can still use push-pull during outputs and write data. When you get ready to do a read type operation you simply put the port mode register back to input mode for those signal lines that will be driven by the peripheral during the read pulse. After the read strobe the port mode can be put back to push-pull output. Indeed you have to do it this way anyway for MCUs that are non-8051 and lacking the ability to support quasi-bidirectional I/O pins. ------------------- Side Bar Comment: I was reading some information about the newer Atmel AT89LP series of single clocker parts and find that on those parts the I/O pins come up by default as strict inputs. If one desires the support for the legacy style quasi-bidirectional pins one has to program port mode registers to act that way intentionally. It seems, from an Atmel WhitePaper, that this must be done as a means of putting the part into the lowest power mode out of reset. Michael Karas |