SLAZ271AB October   2012  – May 2021 MSP430F5327

 

  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.      PN80
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC25
    2. 6.2  ADC27
    3. 6.3  ADC29
    4. 6.4  ADC42
    5. 6.5  ADC69
    6. 6.6  BSL6
    7. 6.7  BSL7
    8. 6.8  COMP10
    9. 6.9  CPU21
    10. 6.10 CPU22
    11. 6.11 CPU23
    12. 6.12 CPU26
    13. 6.13 CPU27
    14. 6.14 CPU28
    15. 6.15 CPU29
    16. 6.16 CPU30
    17. 6.17 CPU31
    18. 6.18 CPU32
    19. 6.19 CPU33
    20. 6.20 CPU34
    21. 6.21 CPU35
    22. 6.22 CPU37
    23. 6.23 CPU39
    24. 6.24 CPU40
    25. 6.25 CPU47
    26. 6.26 DMA4
    27. 6.27 DMA7
    28. 6.28 DMA8
    29. 6.29 DMA10
    30. 6.30 EEM9
    31. 6.31 EEM11
    32. 6.32 EEM13
    33. 6.33 EEM14
    34. 6.34 EEM15
    35. 6.35 EEM16
    36. 6.36 EEM17
    37. 6.37 EEM19
    38. 6.38 EEM21
    39. 6.39 EEM23
    40. 6.40 FLASH33
    41. 6.41 FLASH34
    42. 6.42 FLASH35
    43. 6.43 FLASH37
    44. 6.44 JTAG20
    45. 6.45 JTAG26
    46. 6.46 JTAG27
    47. 6.47 LDO1
    48. 6.48 MPY1
    49. 6.49 PMAP1
    50. 6.50 PMM9
    51. 6.51 PMM10
    52. 6.52 PMM11
    53. 6.53 PMM12
    54. 6.54 PMM14
    55. 6.55 PMM15
    56. 6.56 PMM17
    57. 6.57 PMM18
    58. 6.58 PMM20
    59. 6.59 PORT15
    60. 6.60 PORT16
    61. 6.61 PORT19
    62. 6.62 PORT24
    63. 6.63 RTC3
    64. 6.64 RTC6
    65. 6.65 SYS10
    66. 6.66 SYS12
    67. 6.67 SYS14
    68. 6.68 SYS16
    69. 6.69 TAB23
    70. 6.70 USCI26
    71. 6.71 USCI30
    72. 6.72 USCI31
    73. 6.73 USCI34
    74. 6.74 USCI35
    75. 6.75 USCI39
    76. 6.76 USCI40
    77. 6.77 WDG4
  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
        }
    }
}