Hello
I'm trying to sending some data from UART1 on imx257 PDK board. The purpose is just sending some data, no interrupt, no receive, very simple.
The register setting is as below. But I have found a very strange behavior:
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| // UART1 Init |
| UCR2_1_bit.SRST = 0; //reset |
| UCR1_1_bit.UARTEN = 1; //enable UART |
| UFCR_1_bit.RFDIV = 5; | // Divide input clock by 1 |
| //ONEMS_1 = HCLK /((PCDR3_bit.PERDIV15+1) + 1000); |
| UBIR_1 = 1152-1; |
| UBMR_1 = 41562-1; |
| //USR1_1 = 0xFFFFFFFF; | // clear pending interrupts |
| //USR2_1 = 0xFFFFFFFF; | // clear pending interrupts |
| //IOMUXC_SW_MUX_CTL_PAD_UART1_RXD_bit.MUX_MODE = ALT0_MUX_MODE; |
| //IOMUXC_SW_MUX_CTL_PAD_UART1_TXD_bit.MUX_MODE = ALT0_MUX_MODE; |
| UCR2_1_bit.IRTS = 1; //ignore RTS pin |
| UCR2_1_bit.WS = 1; //8 bit |
| //UCR2_1_bit.PREN = 1; //prity En |
| UCR2_1_bit.TXEN = 1; //enable Tx |
| UCR3_1_bit.RXDMUXSEL = 1; //enable RXD |
| UTXD_1 = 0x000000AA; //set data |
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After writing data to UTXD:
1. The TXFE (Transmit Buffer FIFO Empty) : 1-->0 and keeping at 0
2. The TXDC (Transmitter Complete) : 1-->0 and keeping at 0
3. The TXEMPTY (TxFIFO Empty): 1-->0 and keeping at 0
There is no any data output on TXD pin at first. But when I push reset on IAR debugger, the data shows up on the TXD.
Can any body tell me is there any setting should be done for UART Tx function?
(Clock for UART has been enabled, IOMUX use default value)
Thank you!
Original Attachment has been moved to: UART_SDMA.zip
