An example of using DMA on Tx of UART for Kinetis K20

• Jul 24,2013
  • Use TXDMA in UART1 only. Debug UART0 will be different
  • Use DMA1 'as is' It will allocate and enable the necessary channels, called from the DMA xfer descriptor
  • Merge a single "DMAT_UART", at init will call the DMA1_init

MH - Jul, 11,2013

• Jul 16, using this PEX to generate most of the Peripherals for Profibus (deprecate Serials, Serial, Single Serial, etc) UART0, UART1 -TX DMA -RX is one-by-one isr. Fixed settings 11500,n,8,1
  UART2 (and UART3,UART4 on final) here is 9600,8,n,1 Periodic timer using PIT, 200Hz (5mZ)

  All initialization code is in cpu.c

• Jul 15, make cpu more compatible for merging (minor clock settings)

• Jul15: Added second port, both has DMA.

• Spare DMA channels 0 & 1 for time trigger and use 4 & 5 for UART 0/1.

• Add third port to have source code to merge

MONITOR:

• Toggling TP1 every main loop
• Toggling TP2 on DMA complete (it happen actually 2 bytes before trsnmission is completed) ( The DMA1 component is 'freezed' as any added code will be erased every time PEX generates code) Something like this to toggle pin TP2: GPIO1_ToggleFieldBits(GPIO1_Ptr, TEST_POINTS, 0x02U);

Test port Monitor on TWR elevator TP1 PTB18 (A22) TP2 PTB19 (A23) TP3 PTB20 (B23) TP4 PTB21 (A11) TP5 PTB22 (A10)

UART0 TX(PTD7) RX(PTD6), 115200,8,n,1 - Rx Reads char isr -one by one-

A rec commands does the following with the As1TxBuffer[]: '~' Fills the As1TxBuffer block with consecutive data 1,2,3,..TX_MAX '1' Sends first 10, '2' sends first 50, '3' sends all TX_MAX buffer Any others is stored in As1TxBufferptr++] \r Sends ptr bytes starting at As1TxBuffer[0], and resets ptr=0

/// @TODO Use the Transmit Complete flag to test TX-driver (RS485)