MC68HC58 Motorola, MC68HC58 Datasheet - Page 54

• Manufacturer Part Number: MC68HC58
• Description: Data Link Controller
• Manufacturer: Motorola

4.2.2.4 Initialization
4-10
SCLK
NOTE: SCLK NORMALLY LOW (POLARITY = 0), PHASE = 0
NOTE: SCLK NORMALLY HIGH (POLARITY = 1), PHASE = 1
SOMI
SIMO
SOMI
SCLK
SIMO
MOTOROLA
CS
CS
Before the DLC is used for transmission or reception, it must be initialized. Initialization
is performed by loading a configuration data byte into the configuration byte register
with the “load as configuration byte—immediate” command. Once the configuration
byte is loaded following a reset of the DLC, the host can load message bytes to be
transmitted onto the J1850 bus into the DLC. Transmission will not begin until the DLC
determines that an idle bus condition exists on the J1850 bus. Figure 4-8 illustrates a
basic host/DLC initialization routine.
S7
X7
S7
X7
S6
X6
S6
X6
Use the “load as configuration byte—immediate” command byte bit
combination only after a reset, for test purposes, or for changing the
interrupt mode or mask during normal operation. In the absence of
these conditions, use the “load as configuration byte” command.
DATA VALID IN THIS TIME PERIOD
DATA VALID IN THIS TIME PERIOD
S5
X5
S5
X5
Figure 4-7 SPI Transfer — Clock Polarity High
Figure 4-6 SPI Transfer — Clock Polarity Low
S4
X4
S4
X4
DATA LINK CONTROLLER OPERATION
S3
X3
S3
X3
S2
X2
S2
X2
S1
X1
S1
X1
S0
X0
S0
X0
NOTE
R7
C7
R7
C7
R6
C6
R6
C6
R5
C5
R5
C5
R4
C4
R4
C4
COMMAND BYTE LATCHED
IN AT THIS POINT, AND ITS
CONTENTS WILL BE ACTED
ON WITHIN 2 S
COMMAND BYTE LATCHED
IN AT THIS POINT, AND ITS
CONTENTS WILL BE ACTED
ON WITHIN 2 S
R3
C3
R3
C3
R2
C2
R2
C2
TECHNICAL DATA
DLC SPI TRANSFER 1
DLC SPI TRANSFER 2
R1
C1
R1
C1
MC68HC58
R0
C0
R0
C0