HI-3110 HOLTIC [Holt Integrated Circuits], HI-3110 Datasheet - Page 19

• Manufacturer Part Number: HI-3110
• Description: Avionics CAN Controller with Integrated Transceiver
• Manufacturer: HOLTIC [Holt Integrated Circuits]

BTR0 defines the value of the Re-synchronization Jump Width (SJW) and the Baud Rate Prescaler (BRP). This register can be read
anytime and written only in init mode (MODE<2:0> bits set to <1xx> in the CTRL0 register).
Bit Name
7-6 SJW1:0
5-0 BRP5:0
BIT TIMING REGISTER 0: BTR0
(Write, SPI Op-code 0x18)
(Read, SPI Op-code 0xD6)
R/W
R/W
R/W
Default Description
0
0
Re-synchronization Jump Width bits <1:0>.
These bits are used to compensate for phase shifts between different clock oscillators on the
bus. They define the maximum number of time quanta (Tq) a bit can be shortened or
lengthened to allow a node achieve re-synchronization to the edge of an incoming signal.
Note that one time quantum (Tq) is the single unit of time within a bit time (see Bit Timing
section).
Note:
Baud Rate Prescaler bits <5:0>.
The baud rate prescaler relates the system oscillator frequency, f
described in the bit timing section.
ARINC 825 states that the Re-synchronization Jump Width shall be 1 Tq
HOLT INTEGRATED CIRCUITS
SJW bits <1:0>
BRP bits <5:0>
HI-3110
MSB
7
00: SJW = 1 Tq
01: SJW = 2 Tq
10: SJW = 3 Tq
11: SJW = 4 Tq
000000: BRP = 1
000001: BRP = 2
000010: BRP = 3
000011: BRP = 4
111111: BRP = 64
19
6
5
.
etc.
.
4
3
2
1
LSB
0
OSC
, to the CAN bit time as