Posted on July 21, 2005 at 12:25I propose that forum members share their discoveries and oddities of the STR71x parts.
There are many common problems and sharing the simple (in hindsight) problems and solutions would benefit all. Knowing ahead of time a problem may exist (even without a solution) can save much time.
1) Alternate function INPUT pins. STR711 reference manual page 67 indicates these pins can be set as AF_out or GPIO input.
''• For AF input, the port bit can be either in Input or AF configuration.''
This is not the case. Inputs used as Alternate Functions (uart RX, timer inputs, spi inputs) must be set for input. The AF configuration appears to be for AF outputs only.
2) USB endpoint resources. The number of endpoints is halved if iso is used. Also, there is no provision for endpoints with same endpoint number/different direction (3 IN and 3 OUT is not possible) This is a serious failing for audio applications and means the device does not meet USB2.0 spec.
-Ian Scanlon
