MC908AS60ACFU Datasheet, PDF (275/414 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Protocol Violation Protection
23.6.2 Interrupt Vectors
The MSCAN08 supports four interrupt vectors as shown in Table 23-1. The vector addresses and the
relative interrupt priority are dependent on the chip integration and to be defined.
Table 23-1. MSCAN08 Interrupt Vector Addresses
Function
Wakeup
Error
Interrupts
Receive
Transmit
Source
WUPIF
RWRNIF
TWRNIF
RERRIF
TERRIF
BOFFIF
OVRIF
RXF
TXE0
TXE1
TXE2
Local
Mask
WUPIE
RWRNIE
TWRNIE
RERRIE
TERRIE
BOFFIE
OVRIE
RXFIE
TXEIE0
TXEIE1
TXEIE2
Global
Mask
I Bit
23.7 Protocol Violation Protection
The MSCAN08 will protect the user from accidentally violating the CAN protocol through programming
errors. The protection logic implements the following features:
• The receive and transmit error counters cannot be written or otherwise manipulated.
• All registers which control the configuration of the MSCAN08 can not be modified while the
MSCAN08 is on-line. The SFTRES bit in the MSCAN08 module control register (see 23.13.1
MSCAN08 Module Control Register 0) serves as a lock to protect the following registers:
– MSCAN08 module control register 1 (CMCR1)
– MSCAN08 bus timing register 0 and 1 (CBTR0 and CBTR1)
– MSCAN08 identifier acceptance control register (CIDAC)
– MSCAN08 identifier acceptance registers (CIDAR0–3)
– MSCAN08 identifier mask registers (CIDMR0–3)
• The TxCAN pin is forced to recessive when the MSCAN08 is in any of the Low Power Modes.
23.8 Low Power Modes
In addition to normal mode, the MSCAN08 has three modes with reduced power consumption: Sleep, Soft
Reset and Power Down modes. In Sleep and Soft Reset mode, power consumption is reduced by
stopping all clocks except those to access the registers. In Power Down mode, all clocks are stopped and
no power is consumed.
The WAIT and STOP instructions put the MCU in low power consumption stand-by modes. summarizes
the combinations of MSCAN08 and CPU modes. A particular combination of modes is entered for the
given settings of the bits SLPAK and SFTRES. For all modes, an MSCAN wake-up interrupt can occur
only if SLPAK=WUPIE=1.
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Freescale Semiconductor
275