z16f2811 ZiLOG Semiconductor, z16f2811 Datasheet - Page 159

• Manufacturer Part Number: z16f2811
• Description: High Performance Microcontrollers
• Manufacturer: ZiLOG Semiconductor

PS022006-0207
LIN-UART Interrupts
If the CPU is in HALT or OPERATIONAL mode, the LIN-UART (if enabled) times the
duration of the Wake-up and provides an interrupt following the end of the break sequence
if the duration is ≥ 4 bit times. The total duration of the Wake-up message in bit times is
obtained by reading the
message is detected, the LIN-UART is placed (by software) into either Lin Master or Lin
Slave Wait for Break states as appropriate. If the break duration exceeds fifteen bit times,
the
Lin Sleep state is selected by software setting
move from an active state to sleep state is based on the LIN messages as interpreted by the
software.
LIN Slave Operation
LIN SLAVE mode is selected by setting the bits
LinState[1:0] = 01b
message by the Break which appears to the slave as a break of at least 11 bit times in
duration. The LIN-UART detects the Break and generates an interrupt to the CPU. The
duration of the Break is observable in the
register. A Break of less than 11 bit times in duration does not generate a break interrupt
when the LIN-UART is in “Wait for Break” state. If the Break duration exceeds 15 bit
times, the
Following the Break the LIN-UART hardware automatically transits to the autobaud state,
where it autobauds by timing the duration of the first 8 bit times of the Synch character as
defined in the standard. At the end of the autobaud period, the duration measured by the
BRG counter (auto baud period divided by 8) is automatically transferred to the baud
reload high and low registers if the
counter overflows before reaching the start of bit 7 in the autobaud sequence the autobaud
overrun error interrupt occurs, the OE bit in the Status0 register is set and the baud reload
registers are not updated. To autobaud within 2% of the master’s baud rate, the slave system
clock must be minimum 100 times the baud rate. To avoid an autobaud overrun error, the
system clock must not be greater than 2
bit prescaler when counting the 8 bit times of the autobaud sequence).
Following the Synch character, the LIN-UART hardware transits to the active state, where
the Identifier character is received and the characters of the response section of the message
are sent or received. The slave remains in the active state until a Break is received or the
software forces a state change. When it is in active State (autobaud has completed), a Break
of 10 or more bit times is recognized and a transition to the autobaud state is caused.
The LIN-UART features separate interrupts for the transmitter and receiver. In addition,
when the LIN-UART primary functionality is disabled, the BRG also functions as a basic
timer with interrupt capability.
RxBreakLength
RxBreakLength
field contains the value
RxBreakLength
(Wait for Break state). The LIN slave detects the start of a new
P R E L I M I N A R Y
field contains the value
ABEN
19
bit of the LIN control register is set. If the BRG
RxBreakLength
field in the mode status register. After a Wake-up
times the baud rate (16 bit counter following 3-
LinState[1:0] = 00
FH
LMST
.
FH
=
.
0
,
LSLV
field of the mode status
Product Specification
=
ZNEO
1
,
. The decision to
ABEN
™
=
Z16F Series
1
or
LIN-UART
0
and
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