|
MC9S08DZ60 Datasheet, PDF (238/396 Pages) Freescale Semiconductor, Inc – Microcontrollers | |||
|
◁ |
Freescaleâs Controller Area Network (S08MSCANV1)
An additional transmit buffer priority register (TBPR) is deï¬ned for the transmit buffers. Within the last
two bytes of this memory map, the MSCAN stores a special 16-bit time stamp, which is sampled from an
internal timer after successful transmission or reception of a message. This feature is only available for
transmit and receiver buffers if the TIME bit is set (see Section 12.3.1, âMSCAN Control Register 0
(CANCTL0)â).
The time stamp register is written by the MSCAN. The CPU can only read these registers.
Table 12-24. Message Buffer Organization
Offset
Address
Register
0x00X0 Identiï¬er Register 0
0x00X1 Identiï¬er Register 1
0x00X2 Identiï¬er Register 2
0x00X3 Identiï¬er Register 3
0x00X4 Data Segment Register 0
0x00X5 Data Segment Register 1
0x00X6 Data Segment Register 2
0x00X7 Data Segment Register 3
0x00X8 Data Segment Register 4
0x00X9 Data Segment Register 5
0x00XA Data Segment Register 6
0x00XB Data Segment Register 7
0x00XC
0x00XD
0x00XE
0x00XF
Data Length Register
Transmit Buffer Priority Register1
Time Stamp Register (High Byte)2
Time Stamp Register (Low Byte)3
1 Not applicable for receive buffers
2 Read-only for CPU
3 Read-only for CPU
Access
Figure 12-23 shows the common 13-byte data structure of receive and transmit buffers for extended
identiï¬ers. The mapping of standard identiï¬ers into the IDR registers is shown in Figure 12-24.
All bits of the receive and transmit buffers are âxâ out of reset because of RAM-based implementation1.
All reserved or unused bits of the receive and transmit buffers always read âxâ.
1. Exception: The transmit priority registers are 0 out of reset.
MC9S08DZ60 Series Data Sheet, Rev. 1 Draft E
238
PRELIMINARY
Subject to Change
Freescale Semiconductor
|
▷ |