CC2540: USART0 Alt. 1 configuration (UART mode)

Sorry USART0 Alt. 1

From

SWRU191F–April 2009–Revised April 2014 

"7.6.4 USART 0
The SFR register bit PERCFG.U0CFG selects whether to use alternative 1 or alternative 2 locations."

Try to refer to discussions in e2e.ti.com/.../1902331

I'm using the SerialBLEBridge project and have modified the hal_board_config.h file. I have removed this original code for UART1 Alt. 2 in UART mode:

#define XNV_SPI_INIT() \
st( \
/* Mode select UART1 SPI Mode as master. */\
U1CSR = 0; \
\
/* Setup for 115200 baud. */\
U1GCR = 11; \
U1BAUD = 216; \
\
/* Set bit order to MSB */\
U1GCR |= BV(5); \
\
/* Set UART1 I/O to alternate 2 location on P1 pins. */\
PERCFG |= 0x02; /* U1CFG */\
\
/* Select peripheral function on I/O pins but SS is left as GPIO for separate control. */\
P1SEL |= 0xE0; /* SELP1_[7:4] */\
/* P1.1,2,3: reset, LCD CS, XNV CS. */\
P1SEL &= ~0x0E; \
P1 |= 0x0E; \
P1_1 = 0; \
P1DIR |= 0x0E; \
\
/* Give UART1 priority over Timer3. */\
P2SEL &= ~0x20; /* PRI2P1 */\
\
/* When SPI config is complete, enable it. */\
U1CSR |= 0x40; \
/* Release XNV reset. */\
P1_1 = 1; \
)

and replaced it with my own code for USART0 Alt. 1 in UART mode:

#define XNV_UART_INIT()\
st( \
/* Mode select UART0 UART Mode as master. */\
U0CSR = 1; \
\
/* Setup for 115200 baud. */\
U0GCR = 11; \
U0BAUD = 216; \
\
/* Set bit order to MSB */\
U0GCR |= BV(5); \
\
/* Set UART0 I/O to alternate 1 location on P0 pins. */\
PERCFG |= 0x00; /* U0CFG */\
\
/* Select peripheral function on I/O pins */\
P0SEL |= 0x0C; /* SELP0_[7:4] */\
)

When I try to build the project I get hundreds of errors.

Have I missed something?

Tony

If you intend to use UART0 alt.1, you should use "PERCFG &= (~0x01)" instead of "PERCFG |= 0x00;" in your code.

I have removed the XNV code from hal_board_config.h and placed the following code in BLE_Bridge_Main:

int main(void)
{
...
// Configure USART0 Alt.1 UART Mode
uartMapPort(1, 0);
...
}

I have taken the uartMapPort(...) function directly from the Design Note DN112 document:

void uartMapPort(unsigned char uartPortAlt, unsigned char uartNum) {

// If UART Port Alternative 1 desired
if(uartPortAlt == 1) {

// If UART0 desired
if (uartNum == 0) {

// Configure UART0 for Alternative 1 => Port P0 (PERCFG.U0CFG = 0)
PERCFG &= ~0x01;

// Configure relevant Port P0 pins for peripheral function:
// P0SEL.SELP0_2/3/4/5 = 1 => RX = P0_2, TX = P0_3, CT = P0_4, RT = P0_5
P0SEL |= 0x3C;

// Configure relevant Port P1 pins back to GPIO function
P1SEL &= ~0x3C;

// Else (UART1 desired)
}
else {

// Configure UART1 for Alternative 1 => Port P0 (PERCFG.U1CFG = 0)
PERCFG &= ~0x02;

// Configure relevant Port P0 pins for peripheral function:
// P0SEL.SELP0_2/3/4/5 = 1 => CT = P0_2, RT = P0_3, TX = P0_4, RX = P0_5
P0SEL |= 0x3C;

// Configure relevant Port P1 pins back to GPIO function
P1SEL &= ~0xF0;
}

// Else (UART Port Alternative 2 desired)
}
else {

// If UART0 desired
if (uartNum == 0) {

// Configure UART0 for Alternative 2 => Port P1 (PERCFG.U0CFG = 1)
PERCFG |= 0x01;

// P1SEL.SELP1_2/3/4/5 = 1 => CT = P1_2, RT = P1_3, RX = P1_4, TX = P1_5
P1SEL |= 0x3C;

// Configure relevant Port P0 pins back to GPIO function
P0SEL &= ~0x3C;

// Else (UART1 desired)
}
else {

// Configure UART1 for Alternative 2 => Port P1 (PERCFG.U1CFG = 1)
PERCFG |= 0x02;

// P1SEL.SELP1_4/5/6/7 = 1 => CT = P1_4, RT = P1_5, TX = P1_6, RX = P1_7
P1SEL |= 0xF0;

// Configure relevant Port P0 pins back to GPIO function
P0SEL &= ~0x3C;
}
}
}

The project now builds and downloads fine but I am still not getting data in my serial terminal (I've verified that I am still receiving data from my Android app).

Is there anything else I need to check?

Tony

I suggest you to use IAR to debug this. You can set a breakpoint right before you want to send UART message and check the correctness of all related registers.

The registers look good...

Don't use while loop to send UART TX.

I've removed the while loop but it makes no difference

Can you show me what's in your sendDataToHost?

What is your NPI_UART_PORT?

It is set to zero...

Everything looks fine. Do you use scope to check P0.3 when you do HalUARTWrite?

I've checked with a scope and am not getting a signal

What CC2540 EVB do you use?

I'm not using an EVB, I am using a custom board