Hi Ian, Welcome to the list.
To me it looks like your not initializing P3 to an output (P3DIR |= BIT0;). I believe the default (after PUC) is input. Because P3 in an input the Flash sees High-Z at !CS and the flash's behavior is probably undefined. Chris Takahashi -----Original Message----- From: Ian Bobbitt [mailto:ibobb...@cs.indiana.edu] Sent: Wednesday, August 18, 2004 10:18 AM To: mspgcc-users@lists.sourceforge.net Subject: [Mspgcc-users] USART1 SPI troubles Hello, I am trying to interface a MSP430F169 to an Atmel AT45DB021B flash. As a first attempt, I am trying to read the status register, which contains a part-specific bit string for size determination, as well as a busy indicator. I have the data lines on USART1, and /CS on P3.0. I have tried the following code to read from the part and output the register on P1, but have been unsuccessful thus far. This is my first MSP430 project. What am I doing wrong, and how can I fix it? #include <msp430x16x.h> #include <stdlib.h> #include <signal.h> #include <io.h> #define nCS_LOW { P3OUT &= ~BIT0; } #define nCS_HIGH { P3OUT |= BIT0; } #define WRITE_BYTE(b) { while ((IFG1 & UTXIFG1) == 1); TXBUF1 = b; } int main(void); void setup(void); unsigned char read_status_reg(void); int main(void) { setup(); nCS_HIGH; while(1) { P1OUT = read_status_reg(); } } unsigned char read_status_reg(void) { unsigned char x; nCS_LOW; while((IFG1 & UTXIFG1)); TXBUF1 = 0x57; // read status reg x = RXBUF1; nCS_HIGH; return x; } void setup(void) { WDTCTL = WDTPW|WDTHOLD; // disable watchdog P1DIR = 0xFF; P1OUT = 0xFF; ME2 = USPIE1; UTCTL1 = SSEL1|SSEL0|STC; UCTL1 = CHAR|SYNC|MM; UBR01 = 0x02; UBR11 = 0x00; UMCTL1 = 0x00; P5SEL |= BIT1|BIT2|BIT3; // SPI 5.1-5.3 P3OUT |= BIT0; // nCS output; } ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ Mspgcc-users mailing list Mspgcc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mspgcc-users
