Changes between Version 2 and Version 3 of 802.11/Usage/UART

Timestamp:

Oct 22, 2014, 2:29:16 PM (10 years ago)

Author:

murphpo

Comment:

--

802.11/Usage/UART

@@ -5 +5 @@
 The 802.11 Reference Design hardware implements two MicroBlaze cores, CPU High and CPU Low. Both CPUs have UART cores attached to their peripheral buses. The UARTs act as STDIN and STDOUT for programs running in the CPUs. Every MAC application in the reference design prints boot and debug info the UART. Each application also implements some control via UART input. The pre-application specifics are described below.
 
+You can use the UART in your custom C code by calling {{{xil_printf()}}}. However keep in mind the UART is slow and {{{xil_printf}}} is a blocking call. Printing frequent or long messages will slow down your application, possibly affecting MAC state. Use the UART sparingly, and avoid runtime debug messages whenever possible.
+
 == UART Mux ==
 The WARP v3 board has [wiki:HardwareUsersGuides/WARPv3/UART one UART-USB transceiver]. Refer to the [wiki:howto/USB_UART USB-UART Howto] for instructions on setting up your PC to use the USB-UART interface.
@@ -10 +12 @@
 The 802.11 Reference Design implements a 2:1 mux which allows either CPU's UART to use the UART-USB connection. The mux is controlled by the right-most switch on the user IO DIP switch. Set the switch high (up) to select the CPU High UART, low to select the CPU Low UART. The UART mux responds immediately. You can safely change the UART selection at runtime.
 
-== AP UART ==
+The UART mux is implemented in Verilog; the source is in [browser:/PlatformSupport/CustomPeripherals/pcores/uart_mux_v1_00_a the repository].
 
-The normal UART output on boot of the AP application is:
+== WLAN MAC High Framework Output ==
+
+On booth the MAC High Framework prints status messages as it initializes:
+
 {{{
------ Mango 802.11 Reference Design -----
------ v1.0 ------------------------------
------ wlan_mac_ap -----------------------
-
 ------------------------
 DRAM SODIMM Detected
@@ -38 +39 @@
   Channel : 1
   MAC Addr: 40-D8-55-04-21-4A
+}}}
+
+These messages include initialization of the DRAM contents (with Tx queues, BSS Info entries and Ethernet DMA buffer descriptors) and the wlan_exp framework.
+
+== AP UART ==
+
+The normal UART output on boot of the AP application is:
+{{{
+----- Mango 802.11 Reference Design -----
+----- v1.0 ------------------------------
+----- wlan_mac_ap -----------------------
+