MC9S12XDP512CAL Freescale, MC9S12XDP512CAL Datasheet - Page 465

• Manufacturer Part Number: MC9S12XDP512CAL
• Manufacturer: Freescale

Specifications of MC9S12XDP512CAL

• Cpu Family: HCS12
• Device Core Size: 16b
• Frequency (max): 40MHz
• Interface Type: CAN/I2C/SCI/SPI
• Total Internal Ram Size: 32KB
• # I/os (max): 91
• Number Of Timers - General Purpose: 12
• Operating Supply Voltage (typ): 2.5/5V
• Operating Supply Voltage (max): 2.75/5.5V
• Operating Supply Voltage (min): 2.35/3.15V
• On-chip Adc: 2(16-chx10-bit)
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 112
• Package Type: LQFP
• Program Memory Type: Flash
• Program Memory Size: 512KB
• Lead Free Status / RoHS Status: Compliant

If the bus clock is generated from a PLL, it is recommended to select the oscillator clock rather than the
bus clock due to jitter considerations, especially at the faster CAN bus rates.
For microcontrollers without a clock and reset generator (CRG), CANCLK is driven from the crystal
oscillator (oscillator clock).
A programmable prescaler generates the time quanta (Tq) clock from CANCLK. A time quantum is the
atomic unit of time handled by the MSCAN.
A bit time is subdivided into three segments as described in the Bosch CAN specification. (see
Figure
Freescale Semiconductor
•
•
•
10-44):
SYNC_SEG: This segment has a fixed length of one time quantum. Signal edges are expected to
happen within this section.
Time Segment 1: This segment includes the PROP_SEG and the PHASE_SEG1 of the CAN
standard. It can be programmed by setting the parameter TSEG1 to consist of 4 to 16 time quanta.
Time Segment 2: This segment represents the PHASE_SEG2 of the CAN standard. It can be
programmed by setting the TSEG2 parameter to be 2 to 8 time quanta long.
Transmit Point
SYNC_SEG
1
Bit Rate
NRZ Signal
Figure 10-44. Segments within the Bit Time
MC9S12XDP512 Data Sheet, Rev. 2.21
(PROP_SEG + PHASE_SEG1)
Tq
=
=
8 ... 25 Time Quanta
-------------------------------------------------------------------------------- -
Time Segment 1
number of Time Quanta
= 1 Bit Time
----------------------------------------------------- -
Prescaler value
4 ... 16
Chapter 10 Freescale’s Scalable Controller Area Network (S12MSCANV3)
f
CANCLK
f
Tq
Sample Point
(single or triple sampling)
Time Segment 2
(PHASE_SEG2)
2 ... 8
Eqn. 10-2
Eqn. 10-3
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