MC68HC58 Motorola, MC68HC58 Datasheet - Page 45

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

4.1 Operating Modes
MC68HC58
TECHNICAL DATA
This section explains the operation of the MC68HC58 DLC. SAE J1850 bus interface
and general operation is the same for both the parallel and serial modes, but the meth-
od of transferring information between the host MCU and the DLC differs. Separate
discussions of serial and parallel host MCU interfaces follow the general topics. SEC-
TION 5 CONTROL AND STATUS CODES examines the specific information ex-
changed by the host MCU and the DLC.
The DLC has six main modes of operation which interact with the power supplies, the
J1850 bus interface, and the host MCU interface. Refer to Figure 4-1.
HOST LOADS NORMAL MODE BIT COMBINATION/
HOST LOADS 4X MODE BIT COMBINATION
RECEPTION OF BREAK SYMBOL ON BUS
HOST SENDS “LOAD AS LAST BYTE” COMMAND
RST ASSERTED
(FROM ANY MODE)
4X MODE
SECTION 4 DATA LINK CONTROLLER OPERATION
Figure 4-1 DLC Operating Modes
DATA LINK CONTROLLER OPERATION
V
DD
V
DLC
(MIN.)
POWER OFF
NORMAL
BLOCK
RESET
MODE
HOST FILLS TXFIFO WITHOUT INDICATING LAST BYTE
V
RESET ASSERTED
RESET NEGATED/CONFIGURATION BYTE
LOADED INTO DEVICE
DD
V
NETWORK ACTIVITY/HOST READS STATUS BYTE
HOST SENDS “ENTER STANDBY MODE” COMMAND
DLC
(MIN.)
STANDBY
MOTOROLA
DLC OP MODES
4-1