Section 20 Controller Area Network
Page 1070 of 2108 R01UH0134EJ0400 Rev. 4.00
Sep 24, 2014
SH7262 Group, SH7264 Group
The following settings were used in the above example:
rep_factor
(register)
Offset TTW[1:0] MBC[2:0]
Mailbox-24 3'b001 6'b000000 2'b00 3'b000
Mailbox-25 3'b000 6'b000000 2'b10 3'b000
Mailbox-26 3'b000 6'b000000 2'b10 3'b000
Mailbox-27 3'b000 6'b000000 2'b11 3'b000
Mailbox-28 3'b010 6'b000001 2'b00 3'b000
Mailbox-29 3'b011 6'b000110 2'b01 3'b000
Mailbox-30 3'b111
Mailbox-31 3'b011
CMAX = 3'b011, TXPR[30] = 0
During merged arbitrating window, request by time-triggered transmission is served in the way of
FCFS (First Come First Served). For example, if Mailbox-25 cannot be transmitted between Tx-
Trigger Time 25 (TTT25) and TTT26, Mailbox-25 has higher priority than Mailbox-26 between
TTT26 and 28.
MBC needs to be set into 3'b111, in order to disable time-triggered transmission. If this module is
Time Master, MBC[30] has to be 3'b000 and time reference window is automatically recognized
as arbitrating window.
Timer Operation
Figure 20.23 shows the timing diagram of the timer. By setting Tx-Trigger Time = n, time trigger
transmission starts between CYCTR = n + 2 and
CYCTR = n + 3.
