Diff: MAX11043/MAX11043.h

Revision:

67:5b8a495dda1c

Parent:

66:3fe92f6f1cfa

Child:

68:ffee1e54d3fe

--- a/MAX11043/MAX11043.h	Wed Feb 19 22:47:05 2020 +0000
+++ b/MAX11043/MAX11043.h	Thu Feb 20 01:16:25 2020 +0000
@@ -183,8 +183,17 @@
  *
  * // example code declare SPI interface
  * #if defined(TARGET_MAX32625MBED)
- * SPI spi(SPI1_MOSI, SPI1_MISO, SPI1_SCK); // mosi, miso, sclk spi1 TARGET_MAX32625MBED: P1_1 P1_2 P1_0 Arduino 10-pin header D11 D12 D13
- * DigitalOut spi_cs(SPI1_SS); // TARGET_MAX32625MBED: P1_3 Arduino 10-pin header D10
+ * // TODO1: support SPI hardware-controlled CS instead of GPIO CS (mbed)
+ * // 2020-02-19 attempting to improve SPI CS timing.
+ * // Currently CS envelope is 23us (11.4us before SCLK and 8.6us after SCLK).
+ * // MAX11043 slowest EOC rate is 9us.
+ * // Trying to use SPI-controlled CS configuration. Not working yet.
+ * SPI spi(SPI1_MOSI, SPI1_MISO, SPI1_SCK, SPI1_SS); // mosi, miso, sclk spi1 TARGET_MAX32625MBED: P1_1 P1_2 P1_0 Arduino 10-pin header D11 D12 D13 D10
+ * DigitalOut spi_cs(NC); // TARGET_MAX32625MBED: not connected
+ * // PinName NC means NOT_CONNECTED; DigitalOut::is_connected() returns false
+ * // compile/link but runtime error Assertion failed: obj->name != (PinName)NC
+ * // so something is incorrectly trying to drive the CS pin, which is illegal since it's NC
+ * // TODO: add m_cs_pin.is_connected() guard before writing m_cs_pin = m_SPI_cs_state
  * #elif defined(TARGET_MAX32600MBED)
  * SPI spi(SPI2_MOSI, SPI2_MISO, SPI2_SCK); // mosi, miso, sclk spi1 TARGET_MAX32600MBED: Arduino 10-pin header D11 D12 D13
  * DigitalOut spi_cs(SPI2_SS); // Generic: Arduino 10-pin header D10