ST72561J9-Auto STMicroelectronics, ST72561J9-Auto Datasheet - Page 185

• Manufacturer Part Number: ST72561J9-Auto
• Description: 8-bit MCU for automotive
• Manufacturer: STMicroelectronics

Specifications of ST72561J9-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years at 55 °C
• 5 Power Saving Modes: halt, auto wake up from halt, active halt, wait and slow

ST72561-Auto
15.9.9
15.9.10
15.9.11
Error due to LIN synch measurement
The LIN synch field is measured over eight bit times.
This measurement is performed using a counter clocked by the CPU clock. The edge
detections are performed using the CPU clock cycle.
This leads to a precision of 2 CPU clock cycles for the measurement which lasts 16*8*LDIV
clock cycles.
Consequently, this error (D
2 / (128*LDIV
LDIV
rate, taking into account the maximum deviation of +/-15%.
Error due to baud rate quantization
The baud rate can be adjusted in steps of 1 / (16 * LDIV). The worst case occurs when the
“real” baud rate is in the middle of the step.
This leads to a quantization error (D
Impact of clock deviation on maximum baud rate
The choice of the nominal baud rate (LDIV
(D
Consequently, at a given CPU frequency, the maximum possible nominal baud rate
(LPR
equation:
D
Example:
A nominal baud rate of 20Kbits/s at T
LDIV
D
D
LIN slave systems
For LIN slave systems (the LINE and LSLV bits are set), receivers wake up by LIN synch
break or LIN Identifier detection (depending on the LHDM bit).
Hot plugging feature for LIN slave nodes
In LIN slave mute mode (the LINE, LSLV and RWU bits are set) it is possible to hot plug to a
network during an ongoing communication flow. In this case the SCI monitors the bus on the
RDI line until 11 consecutive dominant bits have been detected and discards all the other
bits received.
TRA
MEAS
QUANT
QUANT
MIN
MIN
MIN
+ 2 / (128 * LDIV
= 2 / (128 * LDIV
) should be chosen with respect to the maximum tolerated deviation given by the
= 1 / (2 * 16 * LDIV
) and the measurement error (D
corresponds to the minimum LIN prescaler content, leading to the maximum baud
= 25 - 0.15*25 = 21.25
MIN
).
MIN
MIN
) + 1 / (2 *16 * LDIV
MEAS
MIN
) * 100 = 0.00073%
LINSCI serial communication interface (LIN master/slave)
Doc ID 12370 Rev 8
) * 100 = 0.0015%
) is equal to:
QUANT
CPU
MEAS
= 125ns (8 MHz) leads to LDIV
) equal to 1 / (2*16*LDIV
NOM
). The worst case occurs for LDIV
MIN
) will influence both the quantization error
) + D
REC
+ D
TCL
< 3.75%
MIN
).
NOM
= 25d.
MIN
.
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