Hi All!
I have a problem with USCI_B0 init control.
NOTE: Initializing or re-configuring the USCI module The recommended USCI initialization/reconfiguration process is:
1. Set UCSWRST ( BIS.B #UCSWRST,&UCxCTL1).
2. Initialize all USCI registers with UCSWRST = 1 (including UCxCTL1).
3. Configure ports.
4. Clear UCSWRST via software (BIC.B #UCSWRST,&UCxCTL1).
quotation: slau208e_MSP430x5xx Family User's Guide (Rev. E); page 523 <http://focus.ti.com/lit/ug/slau208e/slau208e.pdf>
MY CODE ( compiler GCC: Build date: 20081230 Binutils version: 2.18 (with patches) GCC version: 3.2.3 (with patches) GDB version: 6.8 (with atches) ):
cli();
//configure SDA and SCL pins
P3OUT &=~ ( MASK_SDA | MASK_SCL );
//P3.1 & P3.2 set low level
P3SEL |= ( MASK_SDA | MASK_SCL );
//P3.1 & P3.2 config as SDA & SCL
// P3DIR |= ( MASK_SDA | MASK_SCL ); //P3.1 & P3.2 config as output
UCB0I2CIE =
0x00;
UCB0IE =
0x00;
// HOLD I2C MODULE IN RESET
UCB0CTL1 |= I2C_UCSWRST;
//Hold I2C module in reset
// configure uart registers in I2C mode
UCB0CTL0 |= ( UCSYNC + UCMODE1 + UCMODE0 );
//Synchronous mode; I2C mode; Master mode;
UCB0CTL1 |= ( UCSSEL1 + UCSSEL0 );
//BRCLK = SMCLK
UCB0BR0 =
80; //(UCB0BR0+UCB0BR1*256)
UCB0BR1 =
0; //I2C_clk_SCL = 8Mhz/(80+0) = 100kHz
UCB0I2CSA =
0x50; //Load Slave address 0b1010000 (for 24C256_eeprom)
//RELEASE I2C MODULE
UCB0CTL1 &=~ I2C_UCSWRST;
//Release I2C module from reset
UCB0CTL1 =
0xC0;
__asm__ __volatile__(
"BIC.B #0x01, &0x05E1" );
UCB0CTL1 ^=
0x01;
//AFTER THIS ACTIONS I2C_UCSWRST bit ( Software reset enable ) DO NOT CLEARED!!!!!! WHY?!
sei();
Please help! How to clear bit UCSWRST? May be may initializing algorithm is incorrect?
