SLAZ187T October   2012  – May 2021 MSP430F2617

 

  1. 1Functional Advisories
  2. 2Preprogrammed Software Advisories
  3. 3Debug Only Advisories
  4. 4Fixed by Compiler Advisories
  5. 5Nomenclature, Package Symbolization, and Revision Identification
    1. 5.1 Device Nomenclature
    2. 5.2 Package Markings
      1.      ZQW113
      2.      PM64
      3.      PN80
      4.      ZCA113
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC25
    2. 6.2  BCL12
    3. 6.3  BCL13
    4. 6.4  BCL15
    5. 6.5  CPU8
    6. 6.6  CPU16
    7. 6.7  CPU19
    8. 6.8  DAC4
    9. 6.9  DMA3
    10. 6.10 DMA4
    11. 6.11 DMA13
    12. 6.12 FLASH19
    13. 6.13 FLASH24
    14. 6.14 FLASH25
    15. 6.15 FLASH27
    16. 6.16 FLASH36
    17. 6.17 JTAG23
    18. 6.18 PORT10
    19. 6.19 PORT12
    20. 6.20 TA12
    21. 6.21 TA16
    22. 6.22 TA21
    23. 6.23 TAB22
    24. 6.24 TB2
    25. 6.25 TB16
    26. 6.26 TB24
    27. 6.27 USCI20
    28. 6.28 USCI21
    29. 6.29 USCI22
    30. 6.30 USCI23
    31. 6.31 USCI24
    32. 6.32 USCI25
    33. 6.33 USCI26
    34. 6.34 USCI27
    35. 6.35 USCI30
    36. 6.36 USCI34
    37. 6.37 USCI35
    38. 6.38 USCI40
    39. 6.39 XOSC5
    40. 6.40 XOSC8
  7. 7Revision History

USCI34

USCI Module

Category

Functional

Function

I2C multi-master transmit may lose first few bytes.

Description

In an I2C multi-master system (UCMM =1), under the following conditions:

(1)the master is configured as a transmitter (UCTR =1)

AND

(2)the start bit is set (UCTXSTT =1);

if the I2C bus is unavailable, then the USCI module enters an idle state where it waits and checks for bus release. While in the idle state it is possible that the USCI master updates its TXIFG based on clock line activity due to other master/slave communication on the bus. The data byte(s) loaded in TXBUF while in idle state are lost and transmit pointers initialized by the user in the transmit ISR are updated incorrectly.

Workaround

Verify that the START condition has been sent (UCTXSTT =0) before loading TXBUF with data.

Example:
#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
// Workaround for USCI34
    if(UCB0CTL1&UCTXSTT)
    {
                                                                       // TXData = pointer to the transmit buffer start
                                                                       // PTxData = pointer to transmit in the ISR
        PTxData = TXData;                                   // restore the transmit buffer pointer if the Start bit is set
    }
//
    if(IFG2&UCB0TXIFG)
    {
        if (PTxData < = PTxDataEnd)                      // Check TX byte counter
        {
            UCB0TXBUF = *PTxData++;                 // Load TX buffer
        }
        else
        {
            UCB0CTL1 |= UCTXSTP;                        // I2C stop condition
            IFG2 &= ~UCB0TXIFG;                          // Clear USCI_B0 TX int flag
            __bic_SR_register_on_exit(CPUOFF);      // Exit LPM0
        }
    }
}