C8051F555-IMR Silicon Labs, C8051F555-IMR Datasheet - Page 208

• Manufacturer Part Number: C8051F555-IMR
• Description: 8-bit Microcontrollers - MCU 50 MIPS 16 kB 2 kB CAN2.0 SPI
• Manufacturer: Silicon Labs

Specifications of C8051F555-IMR

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit

C8051F55x/56x/57x
21. Controller Area Network (CAN0)
Important Documentation Note : The Bosch CAN Controller is integrated in the C8051F550/1/4/5, ‘F560/
1/4/5/8/9, and ‘F572/3 devices. This section of the data sheet gives a description of the CAN controller as
an overview and offers a description of how the Silicon Labs CIP-51 MCU interfaces with the on-chip
Bosch CAN controller. In order to use the CAN controller, refer to Bosch’s C_CAN User’s Manual as an
accompanying manual to the Silicon Labs’ data sheet.
The C8051F550/1/4/5, ‘F560/1/4/5/8/9, and ‘F572/3 devices feature a Control Area Network (CAN) con-
troller that enables serial communication using the CAN protocol. Silicon Labs CAN facilitates communica-
tion on a CAN network in accordance with the Bosch specification 2.0A (basic CAN) and 2.0B (full CAN).
The CAN controller consists of a CAN Core, Message RAM (separate from the CIP-51 RAM), a message
handler state machine, and control registers. Silicon Labs CAN is a protocol controller and does not pro-
vide physical layer drivers (i.e., transceivers). Figure 21.1 shows an example typical configuration on a
CAN bus.
Silicon Labs’ CAN operates at bit rates of up to 1 Mbit/second, though this can be limited by the physical
layer chosen to transmit data on the CAN bus. The CAN processor has 32 Message Objects that can be
configured to transmit or receive data. Incoming data, message objects and their identifier masks are
stored in the CAN message RAM. All protocol functions for transmission of data and acceptance filtering is
performed by the CAN controller and not by the CIP-51 MCU. In this way, minimal CPU bandwidth is
needed to use CAN communication. The CIP-51 configures the CAN controller, accesses received data,
and passes data for transmission via Special Function Registers (SFRs) in the CIP-51.
Silicon Labs MCU
CAN Protocol Device
CAN Protocol Device
CANTX
CANRX
CAN
CAN
CAN
Transceiver
Transceiver
Transceiver
Isolation/Buffer (Optional)
Isolation/Buffer (Optional)
Isolation/Buffer (Optional)
CAN_H
R
R
CAN_L
Figure 21.1. Typical CAN Bus Configuration
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