MC9S08DZ60MLF Datasheet, PDF (226/416 Pages) Freescale Semiconductor, Inc – MC9S08DZ60 Series Features

Chapter 12 Freescale’s Controller Area Network (S08MSCANV1)
12.3.2 MSCAN Control Register 1 (CANCTL1)
The CANCTL1 register provides various control bits and handshake status information of the MSCAN
module as described below.
R
W
Reset:
7
CANE
0
6
CLKSRC
5
LOOPB
0
0
= Unimplemented
4
LISTEN
1
3
BORM
0
2
WUPM
0
1
SLPAK
0
0
INITAK
1
Figure 12-5. MSCAN Control Register 1(CANCTL1)
Read: Anytime
Write: Anytime when INITRQ = 1 and INITAK = 1, except CANE which is write once in normal and
anytime in special system operation modes when the MSCAN is in initialization mode (INITRQ = 1 and
INITAK = 1).
Table 12-2. CANCTL1 Register Field Descriptions
Field
Description
7
CANE
6
CLKSRC
5
LOOPB
4
LISTEN
3
BORM
2
WUPM
MSCAN Enable
0 MSCAN module is disabled
1 MSCAN module is enabled
MSCAN Clock Source — This bit defines the clock source for the MSCAN module (only for systems with a clock
generation module; Section 12.5.3.3, “Clock System,” and Section Figure 12-42., “MSCAN Clocking Scheme,”).
0 MSCAN clock source is the oscillator clock
1 MSCAN clock source is the bus clock
Loopback Self Test Mode — When this bit is set, the MSCAN performs an internal loopback which can be used
for self test operation. The bit stream output of the transmitter is fed back to the receiver
internally.Section 12.5.4.6, “Loopback Self Test Mode.
0 Loopback self test disabled
1 Loopback self test enabled
Listen Only Mode — This bit configures the MSCAN as a CAN bus monitor. When LISTEN is set, all valid CAN
messages with matching ID are received, but no acknowledgement or error frames are sent out (see
Section 12.5.4.4, “Listen-Only Mode”). In addition, the error counters are frozen. Listen only mode supports
applications which require “hot plugging” or throughput analysis. The MSCAN is unable to transmit any
messages when listen only mode is active.
0 Normal operation
1 Listen only mode activated
Bus-Off Recovery Mode — This bits configures the bus-off state recovery mode of the MSCAN. Refer to
Section 12.6.2, “Bus-Off Recovery,” for details.
0 Automatic bus-off recovery (see Bosch CAN 2.0A/B protocol specification)
1 Bus-off recovery upon user request
Wake-Up Mode — If WUPE in CANCTL0 is enabled, this bit defines whether the integrated low-pass filter is
applied to protect the MSCAN from spurious wake-up (see Section 12.5.5.4, “MSCAN Sleep Mode”).
0 MSCAN wakes up on any dominant level on the CAN bus
1 MSCAN wakes up only in case of a dominant pulse on the CAN bus that has a length of T_wup
MC9S08DZ60 Series Data Sheet, Rev. 4
226
Freescale Semiconductor