We would like to use an external UART with an 8Bit data- and an 8Bit addressbus. Is it possible to use the EMI in this way? In the datasheet on pages 31/32 there is a Fig. 5 that looks the right way, but i don't find anything about the usage of port 9 in this configuration. Thanks in advance Thomas
The multiplexed mode is O.K. for me. The question is just: can i use the not used (by the UART) address bits (a8..a15) on port 9 for gpio's? Thanks Thomas
you need not to use address ,data bus to interface with UART.Any port in input/output mode will be sufficient.You can keep port8,9 in gpio mode and u can use the port to interface with uart.
please refer to pin description in table4 in the STR9 datasheet. You will see that you can use GPIO9 pins for another function when you configure it in alternate output 1 or its default pin function. Best regards mirou