Rainbow Electronics CAN интерфейс - Manual (Page 30)

BOSCH
ROBERT BOSCH GmbH, Postfach 50, D-7000 Stuttgart 1
Sep. 1991
Part A - page 28
It is twice the sum of the signal’s propagation time on the bus line, the input comparator
delay, and the output driver delay.
PHASE SEG1, PHASE SEG2
These Phase-Buffer-Segments are used to compensate for edge phase errors. These
segments can be lengthened or shortened by resynchronization.
SAMPLE POINT
The SAMPLE POINT is the point of time at which the bus level is read and interpreted
as the value of that respective bit. It’s location is at the end of PHASE_SEG1.
INFORMATION PROCESSING TIME
The INFORMATION PROCESSING TIME is the time segment starting with the
SAMPLE POINT reserved for calculation the subsequent bit level.
TIME QUANTUM
The TIME QUANTUM is a fixed unit of time derived from the oscillator period. There
exists a programmable prescaler, with integral values, ranging at least from 1 to 32.
Starting with the MINIMUM TIME QUANTUM, the TIME QUANTUM can have a length
of
TIME QUANTUM = m * MINIMUM TIME QUANTUM
with m the value of the prescaler.
Length of Time Segments
• SYNC_SEG is 1 TIME QUANTUM long.
• PROP_SEG is programmable to be 1,2,...,8 TIME QUANTA long.
• PHASE_SEG1 is programmable to be 1,2,...,8 TIME QUANTA long.
• PHASE_SEG2 is the maximum of PHASE_SEG1 and the INFORMATION
PROCESSING TIME
• The INFORMATION PROCESSING TIME is less than or equal to 2 TIME QUANTA
long.
The total number of TIME QUANTA in a bit time has to be programmable at least from
8 to 25.
Bit Timing