* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
- * - Neither the name of the Technische Universität Berlin nor the names
+ * - Neither the name of the Titanium Mirror, Inc. nor the names
* of its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
-
+
/**
* This configuration provides the interface for using USCI_B1 in its SPI
* mode.
*
- * @author R. Steve McKown <smckown@gmail.com>
+ * The instantiator should set the blockSize, which represents the maximum
+ * number of bytes the underlying SPI stack will transmit or receive in a
+ * single interrupt service. Increasing the block size decreases SPI
+ * communications time at the expense of reducing system responsiveness to
+ * other events.
+ *
+ * The blockSize is best set by considering the maximum time the SPI stack
+ * should be able to delay other events. A rule of thumb formula would be:
+ *
+ * block_time = block_size / (spi_bitclock/8)
+ *
+ * For example, using a 500KHZ SPI bitclock, a block size of 64 bytes
+ * equates to a block time of 1 ms. Note that this calculation is rough
+ * because it does not take into account ISR overhead and other factors.
+ *
+ * The implementation will use a default blockSize if set to 0 here.
+ *
+ * @author R. Steve McKown <rsmckown@gmail.com>
*/
-
+
#if !defined(__MSP430_HAS_USCI_AB1__)
#error "Target does not have a USCI_B1 peripheral (SPI)"
#endif
-configuration Msp430SpiB1C {
+#include "Msp430Usci.h"
+
+generic configuration Msp430SpiB1C(uint16_t blockSize) {
provides {
interface Resource;
interface ResourceRequested;
interface SpiPacket;
interface ArbiterInfo; /* ??? */
}
- uses interface Msp430UsciSpiConfigure; /* would be nice to use Msp430SpiConfigure, same as USART analog */
+ uses {
+ interface AsyncConfigure<const msp430_usci_spi_t*> as Configure;
+ interface GeneralIO as CSn; /* wire only if a SPI slave only */
+ }
}
implementation {
enum {
CLIENT_ID = unique(MSP430_USCIB1_RESOURCE)
};
- components Msp430SpiP as SpiP;
+ components new Msp430SpiP(blockSize) as SpiP;
SpiByte = SpiP;
SpiPacket = SpiP;
- Msp430UsciSpiConfigure = SpiP;
+ Configure = SpiP;
+ CSn = SpiP;
- components new Msp430UsciA0C() as UsciC;
+ components Msp430UsciB1C as UsciC;
Resource = UsciC.Resource[CLIENT_ID];
ResourceRequested = UsciC.ResourceRequested[CLIENT_ID];
ArbiterInfo = UsciC.ArbiterInfo;
SpiP.STE -> IOC.UCB1STE;
SpiP.SIMO -> IOC.UCB1SIMO;
SpiP.SOMI -> IOC.UCB1SOMI;
- SpiP.SCL -> IOC.UCB1SCL;
+ SpiP.CLK -> IOC.UCB1CLK;
}