I believe I've discovered a bug in DRIVERLIB version 2.91.13.01. In the file usci_b_i2c.c, in the function EUSCI_B_I2C_masterReceiveMultiByteFinish() is the following code:
uint8_t EUSCI_B_I2C_masterReceiveMultiByteFinish (uint16_t baseAddress)
{
//Send stop condition.
HWREG16(baseAddress + OFS_UCBxCTLW0) |= UCTXSTP;
//Wait for Stop to finish
while (HWREG16(baseAddress + OFS_UCBxCTLW0) & UCTXSTP) <--- NOTE NO SEMICOLON
// Wait for RX buffer
while (!(HWREG16(baseAddress + OFS_UCBxIFG) & UCRXIFG)) ;
//Capture data from receive buffer after setting stop bit due to
//MSP430 I2C critical timing.
return (HWREG16(baseAddress + OFS_UCBxRXBUF));
}
I believe there should be a semicolon (;) at the end of the "while (HWREG16(baseAddress + OFS_UCBxCTLW0) & UCTXSTP)" immediately after the "Wait for Stop to finish" comment. The missing semicolon causes the wait-for-stop while statement to also execute the wait-for-RX-buffer while statement, which might be triggering the bus stall errata USCI37 documented in SLAZ382AH. It's noteworthy that the EUSCI_B_I2C_masterReceiveMultiByteFinishWithTimeout() function does have a semicolon at the end of that corresponding line of code.
This appears to affect all DRIVERLIB versions except for the MSP430F5xx_6xx version, where the semicolon is present.
Can someone at TI please confirm?
- Brian
