Differences

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--- memory_map [2021/09/21 21:53] – [IO special functions and usage] Removed incorrect data about io mappings. pulkomandy
+++ memory_map [2021/09/23 22:48] – [UART] pulkomandy
@@ Line 279: / Line 279: @@
   * 115200: FF F1
+Before using the UART, the corresponding PINs need to be configured properly. IOC13 and IOC14 must be set to "special"/"mask" mode to disable the GPIO and assign the pin to UART.
+The example below also forces CTS A (IOC8) low, allowing the first controller port to transmit data. Normally this would only be done after receiving an RTS from said controller.
+	// Enable controller CTS
+	*PORTC_DIR = 0x89c0;
+	*PORTC_ATTR = 0x89c0;
+	*PORTC_DATA = 0xf77f;
+	// Enable Uart RX (controller input)
+	*UART_BAUDRATE_LOW = 0xA0;
+	*UART_BAUDRATE_HIGH = 0xFE;
+	*UART_CONTROL = 0xc3;
+	*UART_STATUS = 3;
+	*PORTC_SPECIAL |= 0x6000; // UART Tx and Rx in "special" mode
+	*PORTC_ATTR |= 0x6000;
+	*PORTC_DIR |= 0x4000;
+Reading from the UART then is quite simple:
+  * Wait until the status register indicates Rx ready (bit 0)
+  * When Rx is ready, read the Rx data register to get the byte
+For transmitting, you need to check if the FIFO is cleared (bit 1 of status register) then you can push your bytes to the transmit register.
 ====== SPI ======