EVB9S08DZ60 Freescale Semiconductor, EVB9S08DZ60 Datasheet - Page 264

• Manufacturer Part Number: EVB9S08DZ60
• Description: BOARD EVAL FOR 9S08DZ60
• Manufacturer: Freescale Semiconductor
• Type: MCUr

Specifications of EVB9S08DZ60

• Contents: Module and Misc Hardware
• Processor To Be Evaluated: S08D
• Data Bus Width: 8 bit
• Interface Type: RS-232, USB
• Silicon Manufacturer: Freescale
• Core Architecture: HCS08
• Core Sub-architecture: HCS08
• Silicon Core Number: MC9S08
• Silicon Family Name: S08D
• Kit Contents: Board Cables CD Power Supply
• Rohs Compliant: Yes
• For Use With/related Products: MC9S08DZ60
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Chapter 12 Freescale’s Controller Area Network (S08MSCANV1)
12.5.5.4
The CPU can request the MSCAN to enter this low power mode by asserting the SLPRQ bit in the
CANCTL0 register. The time when the MSCAN enters sleep mode depends on a fixed synchronization
delay and its current activity:
If sleep mode is active, the SLPRQ and SLPAK bits are set
use SLPAK as a handshake indication for the request (SLPRQ) to go into sleep mode.
When in sleep mode (SLPRQ = 1 and SLPAK = 1), the MSCAN stops its internal clocks. However, clocks
that allow register accesses from the CPU side continue to run.
If the MSCAN is in bus-off state, it stops counting the 128 occurrences of 11 consecutive recessive bits
due to the stopped clocks. The TXCAN pin remains in a recessive state. If RXF = 1, the message can be
read and RXF can be cleared. Shifting a new message into the foreground buffer of the receiver FIFO
(RxFG) does not take place while in sleep mode.
It is possible to access the transmit buffers and to clear the associated TXE flags. No message abort takes
place while in sleep mode.
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If there are one or more message buffers scheduled for transmission (TXEx = 0), the MSCAN will
continue to transmit until all transmit message buffers are empty (TXEx = 1, transmitted
successfully or aborted) and then goes into sleep mode.
If the MSCAN is receiving, it continues to receive and goes into sleep mode as soon as the CAN
bus next becomes idle.
If the MSCAN is neither transmitting nor receiving, it immediately goes into sleep mode.
MSCAN Sleep Mode
The application software must avoid setting up a transmission (by clearing
one or more TXEx flag(s)) and immediately request sleep mode (by setting
SLPRQ). Whether the MSCAN starts transmitting or goes into sleep mode
directly depends on the exact sequence of operations.
Bus Clock Domain
CPU
Sleep Request
SLPAK
Flag
Figure 12-44. Sleep Request / Acknowledge Cycle
SLPRQ
sync.
SLPAK
MC9S08DZ60 Series Data Sheet, Rev. 4
NOTE
SYNC
SYNC
CAN Clock Domain
(Figure
sync.
SLPRQ
SLPAK
12-44). The application software must
MSCAN
in Sleep Mode
SLPRQ
Flag
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