ST7MC2M9 STMicroelectronics, ST7MC2M9 Datasheet - Page 135

• Manufacturer Part Number: ST7MC2M9
• Description: 8-BIT MCU WITH NESTED INTERRUPTS, FLASH, 10-BIT ADC,BRUSHLESS MOTOR CONTROL, 5 TIMERS, SPI, LINSCI(TM)
• Manufacturer: STMicroelectronics

Specifications of ST7MC2M9

• Hdflash Endurance: 100 cycles, data retention
• Clock Sources: crystal/ceramic resonator oscillators and by-pass for external clock, clock security system.
• Four Power Saving Modes: Halt, Active-Halt, Wait and Slow
• Main Clock Controller With: Real time base, Beep and Clock-out capabilities
• Two 16-bit Timers With: 2 input captures, 2 output compares, external clock input, PWM and pulse generator modes
• 8-bit Pwm Auto-reload Timer With: 2 input captures, 4 PWM outputs, output compare and time base interrupt, external clock with event detector

LINSCI™ SERIAL COMMUNICATION INTERFACE (LIN Mode) (cont’d)
LIN PRESCALER FRACTION REGISTER
(LPFR)
Read/Write
Reset Value: 0000 0000 (00h)
Bits 7:4 = Reserved.
Bits 3:0 = LPFR[3:0] Fraction of LDIV
These 4 bits define the fraction of the LIN Divider
(LDIV):
1. When initializing LDIV, the LPFR register must
be written first. Then, the write to the LPR register
7
0
LPFR[3:0]
Eh
Fh
0h
1h
...
0
0
0
Fraction (LDIV)
LPFR
3
14/16
15/16
1/16
...
0
LPFR
2
LPFR
1
LPFR
0
0
will effectively update LDIV and so the clock gen-
eration.
2. In LIN Slave mode, if the LPR[7:0] register is
Examples of LDIV coding:
Example 1: LPR = 27d and LPFR = 12d
This leads to:
Mantissa (LDIV) = 27d
Fraction (LDIV) = 12/16 = 0.75d
Therefore LDIV = 27.75d
Example 2: LDIV = 25.62d
This leads to:
LPFR = rounded(16*0.62d)
= rounded(9.92d) = 10d = Ah
LPR = mantissa (25.620d) = 25d = 1Bh
Example 3: LDIV = 25.99d
This leads to:
LPFR = rounded(16*0.99d)
= rounded(15.84d) = 16d
equal to 00h, the transceiver and receiver input
clocks are switched off.
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