AN2320 Freescale Semiconductor / Motorola, AN2320 Datasheet - Page 13

Manufacturer Part Number

AN2320

Description

Interfacing the MCF5272 to a Standalone CAN Controller

Manufacturer

Freescale Semiconductor / Motorola

Datasheet

1.AN2320.pdf (24 pages)

Freescale Semiconductor, Inc.

Transmitting and Receiving over the MCF5272 QSPI Interface

vary between the different accesses (for example, the minimum time for a read access can be three times as

much as a write access), it may be desirable to change the command RAM entries when switching between

a read transfer and a write transfer. QSPI initialisation code:

void

mcf5272_qspi_init()

{

MCF5272_IMM *imm = mcf5272_get_immp();

/*Set QSPI mode register, 5.5Mbit/s, 8 bit, data change on leading, clock idle high*/

MCF5272_WR_QSPI_QMR(imm,MCF5272_QSPI_QMR_CAN);

/*Set delay after transfer and clock delay*/

MCF5272_WR_QSPI_QDLYR(imm,MCF5272_QSPI_QDLYR_CAN);

/*Clear flags and interrupts*/

MCF5272_WR_QSPI_QIR(imm,MCF5272_QSPI_QIR_CAN);

/*Point to top of command RAM*/

MCF5272_WR_QSPI_QAR(imm,MCF5272_QSPI_QAR_Comm);

/*Set each entry for continuous transfer, 8 bit transfer, to use /CS0 and delays*/

MCF5272_WR_QSPI_QDR(imm,MCF5272_QSPI_QDR_CR_CONT);

}

Writing to the 82C900 register:

/*The address of 82C900 register and data to be written to it are passed*/

void QSPI_SendByte(uint16 CanRegAddr, uint8 Data)

{

MCF5272_IMM *imm = mcf5272_get_immp();

/*Determine 82C900 register address*/

CAN_SetPageReg((uint8)(CanRegAddr>>7));

/*Point to top of Tx RAM*/

Interfacing the MCF5272 to a Standalone CAN Controller

MOTOROLA

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