MB95630H Series
208
FUJITSU SEMICONDUCTOR LIMITED
MN702-00009-1v0-E
CHAPTER 14 LIN-UART
14.4 Interrupts
■
LIN Synch Field Edge Detection Interrupt (8/16-bit Composite Timer Interrupt)
Table 14.4-3 shows the control bits and interrupt sources of the LIN synch field edge detection
interrupt.
●
LIN synch field edge detection interrupt (8/16-bit composite timer interrupt)
In operating mode 3, the LIN synch field edge detection interrupt functions when the LIN-
UART performs LIN slave operation.
After a LIN synch break is detected, the internal signal (LSYN) is set to "1" at the first falling
edge of the LIN synch field, and set to "0" after the fifth falling edge. Between both falling
edges, a 8/16-bit composite timer interrupt is generated, provided that the 8/16-bit composite
timer has been configured to receive internal signals and detect rising edges and falling edges
and the 8/16-bit composite interrupt has been enabled.
The difference in the count values detected by the 8/16-bit composite timer (see Figure 14.4-1)
is equivalent to eight bits of the master serial clock. A new baud rate can be calculated from
this value. After set, a new baud rate becomes effective from the falling edge detected at the
next start bit set.
Figure 14.4-1 Baud Rate Calculation by 8/16-bit Composite Timer
Table 14.4-3 Interrupt Control Bits and Interrupt Sources of LIN Synch Field Edge Detection
Interrupt
Interrupt
request flag
bit
Flag
register
Operating mode
Interrupt source
Interrupt source
enable bit
Interrupt request flag
clear
0
1
2
3
IR
Tn0CR1
×
×
×
❍
First falling edge of the LIN
synch field
Tn0CR1:IE
Write "0" to Tn0CR1:IR
IR
Tn0CR1
×
×
×
❍
Fifth falling edge of the LIN
synch field
❍
: Bit to be used
×
: Unused bit
LIN
s
ynch field
S
top
b
it
RDR
b
it0
RDR
b
it1
RDR
b
it2
RDR
b
it
3
RDR
b
it4
RDR
b
it5
RDR
b
it6
Reception d
a
t
a
D
a
t
a
= 0x55
Intern
a
l
s
ign
a
l
(L
S
YN)
8
/16-
b
it
compo
s
ite timer
C
a
pt
u
re v
a
l
u
e 1
C
a
pt
u
re v
a
l
u
e 2
Difference in co
u
nt v
a
l
u
e
s
= C
a
pt
u
re v
a
l
u
e 2 - C
a
pt
u
re V
a
l
u
e 1
RDR
b
it7
S
t
a
rt
b
it