ST72521 datasheet(137/211 Pages) STMICROELECTRONICS

137 / 211 page

ST72521

137/211

CONTROLLER AREA NETWORK (Cont’d)

BAUD RATE PRESCALER REGISTER (BRPR)

Read/Write in Standby mode

Reset Value: 00h

RJW[1:0] determine the maximum number of time

quanta by which a bit period may be shortened or

lengthened to achieve resynchronization.

tRJW = tCAN * (RJW + 1)

BRP[5:0] determine the CAN system clock cycle

time or time quanta which is used to build up the in-

dividual bit timing.

tCAN = tCPU * (BRP + 1)

Where tCPU = time period of the CPU clock.

The resulting baud rate can be computed by the for-

mula:

Note: Writing to this register is allowed only in

Standby mode to prevent any accidental CAN pro-

tocol violation through programming errors.

BIT TIMING REGISTER (BTR)

Read/Write in Standby mode

Reset Value: 23h

BS2[2:0] determine the length of Bit Segment 2.

tBS2 = tCAN * (BS2 + 1)

BS1[3:0] determine the length of Bit Segment 1.

tBS1 = tCAN * (BS1 + 1)

Note: Writing to this register is allowed only in

Standby mode to prevent any accidental CAN pro-

tocol violation through programming errors.

PAGE SELECTION REGISTER (PSR)

Read/Write

Reset Value: 00h

PAGE[2:0] determine which buffer or filter page is

mapped at addresses 0010h to 001Fh.

RJW1

RJW0

BRP5

BRP4

BRP3

BRP2

BRP1

BRP0

CPU

BR P

()

BS1

BS2

()

------------------------------------------------------------------------------------------------

BS22

BS21

BS20

BS13

BS12

BS11

BS10

000

PAGE

PAGE2

PAGE1

PAGE0

Page Title

Diagnosis

Buffer 1

Buffer 2

Buffer 3

Filters

Reserved

ST72521 数据表(PDF) 137 Page - STMicroelectronics

ST72521 数据表(HTML) 137 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载