mfr4200 Freescale Semiconductor, Inc, mfr4200 Datasheet - Page 183

• Manufacturer Part Number: mfr4200
• Description: Flexray Communication Controllers
• Manufacturer: Freescale Semiconductor, Inc

Freescale Semiconductor
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Table 3-17. Double Transmit Message Buffer Data Collection with State Driven Transmit Operation
The host sends a lock request to a host part buffer of a
double transmit message buffer (it writes LOCK=’1’) and
receives a request acknowledge (read back value of the
LOCK=’1’).
The host part buffer is locked. The host updates the buffer
contents.
The host part buffer is locked. The host updates the buffer
contents.
The host part buffer is locked. The host finished data
update (buffer holds the DATA1), committed the buffer for
transmission (BUFCMT=’1’) and sent an unlock request
(it writes again LOCK=’1’)
Unlock granted.
–
–
The host sends a lock request to a host part buffer of a
double transmit message buffer (it writes LOCK=’1’) but
does not receive a lock request acknowledge (read back
value of the LOCK=’0’) due to the copy process running.
–
double transmit message buffer (it writes LOCK=’1’) and
receives a request acknowledge (read back value of the
LOCK=’1’) and has starts to update data in the host part
buffer.
The host sends a lock request to a host part buffer of a
Host Operations
MFR4200 Data Sheet, Rev. 0
–
The CC starts frames transmission and sends a buffer lock
request for CC part buffer to transmit the frame this buffer
holds.
The CC locked the CC part buffer and transmits the frame
from it
The CC finished transmission and updates the BUFCMT,
VALID and IFLG bits of the CC part buffer
The CC clears the IFLG bit of the host part buffer to ‘0’ and
sets the VALID bit. The CC performs an atomic swap of the
host part and CC part buffers including the BUFCSnR
registers and starts a copy process.
The atomic swap of the host part and CC part buffers is
done. The CC starts the copy process from the new CC
part buffer to the host part buffer. BUFCMT bit of the host
part buffer is ‘1’ until those processes are finished (The
host cannot lock the host part buffer).
The CC continues the copy process and starts frames
transmission. The CC sends a buffer lock request for CC
part buffer to transmit the frame this buffer holds.
The CC continues the copy process.The CC locked the
CC part buffer and transmits the frame from it.
The CC transmits the frame from the CC part buffer. The
CC finished the copy process (The host can lock the
buffer).
The CC transmits the frame from the CC part buffer.
Message Buffer Handling and Operations
CC Operations
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