Hello,
I was testing I2C operation between two development boards(EM430F5137RF900) using sample codes.
I could successfully make the I2C work.
But when i'm trying to communicate with an EEPROM (AT24C1024 From Atmel) i can't detect the ACK from the EEprom.
MY I2C Clock is almost 540 KHz
E2PROM Datasheet:
http://www.atmel.org/dyn/resources/prod_documents/doc1471.pdf
Here is My Code:
SMCLK is 8Mhz
void
I2C_Init(void)
{
//..........
// ACLK = REFO = 32kHz, MCLK = SMCLK = 8MHz//
/* Initialize Ports */
PMAPPWD =
0x02D52;
// Get
write-access to port mapping regs
P2MAP0 = PM_ACLK;
// Map ACLK
output to P2.0
P2MAP2 =
PM_MCLK;
// Map MCLK
output to P2.2
P2MAP4 =
PM_SMCLK;
// Map SMCLK output to P2.4
PMAPPWD =
0;
// Lock port mapping registers
P2DIR |= BIT0 + BIT2 +
BIT4;
// ACLK, MCLK, SMCLK set out
to pins
P2SEL |= BIT0 + BIT2 +
BIT4;
// P2.0,2,4 for debugging
purposes
UCSCTL3 |=
SELREF_2;
// Set DCO FLL reference
= REFO
UCSCTL4 |=
SELA_2;
// Set ACLK =
REFO
__bis_SR_register(SCG0);
// Disable the FLL control
loop
UCSCTL0 =
0x0000;
// Set lowest
possible DCOx, MODx
UCSCTL1 =
DCORSEL_5;
// Select DCO range 16MHz
operation
UCSCTL2 = FLLD_1 +
249;
// Set DCO Multiplier for 8MHz
// (N + 1) * FLLRef = Fdco
// (249 + 1) * 32768 =
8MHz
// Set FLL Div = fDCOCLK/2
__bic_SR_register(SCG0);
// Enable
the FLL control loop
// Worst-case settling time
for the DCO when the DCO range bits have been
// changed is n x 32 x 32 x
f_MCLK / f_FLL_reference. See UCS chapter in 5xx
// UG for optimization.
// 32 x 32 x 8 MHz / 32,768 Hz = 250000 = MCLK cycles for DCO to settle
__delay_cycles(250000);
//............................
PMAPPWD =
0x02D52;
P1MAP3 =
PM_UCB0SDA;
P1MAP2 =
PM_UCB0SCL;
PMAPPWD =
0;
P1SEL |= (BIT2+BIT3);
//............................
UCB0CTL1 |=
UCSWRST;
// Enable SW reset
UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC
; // I2C Master, synchronous mode
UCB0CTL1 = 0xC0 + UCTR + UCSWRST ;
// Use ACLK, keep SW reset
UCB0BR0 = 12;
UCB0BR1 = 0x00;
UCB0I2CSA = 0xA0;
// E2Prom Address
//
UCB0I2COA=0x01a5;
// ----> Master Own Address
UCB0CTL1 &= ~UCSWRST;
Any comment would be appriciated,
Thx
