CP3BT26 Datasheet, PDF (135/278 Pages) National Semiconductor (TI) – Reprogrammable Connectivity Processor with Bluetooth-R, USB, and CAN Interfaces

INTERNAL
DIAGEN
EIT
If the Internal function is enabled, the CANTX
and CANRX pins of the CAN module are inter-
nally connected to each other. This feature
can be used in conjunction with the LOOP-
BACK mode. This means that the CAN mod-
ule can receive its own sent messages
without connecting an external transceiver
chip to the CANTX and CANRX pins; it allows
software to run real stand-alone tests without
any peripheral devices.
0 – Normal mode.
1 – Internal mode.
The Diagnostic Enable bit globally enables or
disables the special diagnostic features of the
CAN module. This includes the following func-
tions:
• LO (Listen Only).
• IGNACK (Ignore Acknowledge).
• LOOPBACK (Loopback).
• INTERNAL (Internal Loopback).
• Write access to hidden receive buffer.
0 – Normal mode.
1 – Diagnostic features enabled.
The Error Interrupt Type bit configures when
the Error Interrupt Pending Bit (CIPND.EIP-
ND) is set and an error interrupt is generated
if enabled by the Error Interrupt Enable
(CIEN.EIEN).
0 – The EIPND bit is set on every error on the
CAN bus.
1 – The EIPND bit is set only if the error state
(CSTPND.NS) changes as a result of in-
crementing either the receive or transmit
error counter.
19.10.7 CAN Timing Register (CTIM)
The Can Timing Register (CTIM) defines the configuration
of the Bit Time Logic (BTL).
15
PSC
98 7 6
32
0
SJW
TSEG1
TSEG2
0
R/W
PSC
The Prescaler Configuration field specifies
the CAN prescaler. The settings are shown in
Table 57
Table 57 CAN Prescaler Settings
PSC6:0
Prescaler
000000
2
000001
3
000010
4
000011
5
000100
6
:
:
1111101
127
1111110
128
1111111
128
SJW
The Synchronization Jump Width field speci-
fies the Synchronization Jump Width, which
can be programmed between 1 and 4 time
quanta (see Table 58).
Table 58 SJW Settings
SJW
Synchronization Jump
Width (SJW)
00
1 time quantum
01
2 time quanta
10
3 time quanta
11
4 time quanta
Note: The settings of SJW must be configured to be small-
er or equal to TSEG1 and TSEG2
135
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