SLAZ091Z October   2012  – May 2021 CC430F5125

 

  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.      RGZ48
    3. 5.3 Memory-Mapped Hardware Revision (TLV Structure)
  6. 6Advisory Descriptions
    1. 6.1  ADC39
    2. 6.2  ADC42
    3. 6.3  ADC69
    4. 6.4  AES1
    5. 6.5  BSL7
    6. 6.6  BSL14
    7. 6.7  COMP10
    8. 6.8  CPU21
    9. 6.9  CPU22
    10. 6.10 CPU36
    11. 6.11 CPU40
    12. 6.12 CPU46
    13. 6.13 CPU47
    14. 6.14 DMA4
    15. 6.15 DMA7
    16. 6.16 DMA10
    17. 6.17 EEM17
    18. 6.18 EEM19
    19. 6.19 EEM23
    20. 6.20 JTAG26
    21. 6.21 JTAG27
    22. 6.22 PMM11
    23. 6.23 PMM12
    24. 6.24 PMM14
    25. 6.25 PMM15
    26. 6.26 PMM18
    27. 6.27 PMM20
    28. 6.28 PMM26
    29. 6.29 PORT15
    30. 6.30 PORT19
    31. 6.31 PORT29
    32. 6.32 RF1A1
    33. 6.33 RF1A2
    34. 6.34 RF1A3
    35. 6.35 RF1A5
    36. 6.36 RF1A6
    37. 6.37 RF1A8
    38. 6.38 SYS12
    39. 6.39 SYS16
    40. 6.40 UCS11
    41. 6.41 USCI26
    42. 6.42 USCI30
    43. 6.43 USCI34
    44. 6.44 USCI35
    45. 6.45 USCI39
    46. 6.46 USCI40
  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
        }
    }
}