mc68hc05x4dw Freescale Semiconductor, Inc, mc68hc05x4dw Datasheet - Page 86

• Manufacturer Part Number: mc68hc05x4dw
• Description: Xc68hc705x4 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

MCAN
acceptance code
register (CACC)
Motorola CAN
MC68HC05X4
NOTE:
Address:
On reception each message is written into the current receive buffer.
The MCU is only signalled to read the message however, if it passes the
criteria in the acceptance code and acceptance mask registers
(accepted); otherwise, the message will be overwritten by the next
message (dropped).
This register can be accessed only when the RR bit in CCNTRL is set.
AC7 – AC0 — Acceptance code bits
Reset:
AC7 – AC0 comprise a user defined sequence of bits with which the
8 most significant bits of the data identifier (ID10 – ID3) are compared.
The result of this comparison is then masked with the acceptance
mask register. Once a message has passed the acceptance criterion
the respective identifier, data length code and data are sequentially
stored in a receive buffer, providing there is one free. If there is no free
buffer, the data overrun condition will be signalled.
On acceptance the receive buffer status bit is set to full and the
receive interrupt bit is set (provided RIE = enabled).
Freescale Semiconductor, Inc.
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Bit 7
AC7
Figure 8. MCAN Acceptance Code (CACC)
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AC6
6
Motorola CAN
AC5
5
AC4
4
Undefined
AC3
3
AC2
2
AC1
1
Bit 0
AC0
18-mcan