LPC4357JBD208E 托盘 LPC1788

3.1 C_CAN.1: Writes to CAN registers write through to other peripherals Introduction: Controller Area Network (CAN) is the definition of a high performance communication protocol for serial data communication. The C_CAN controller is designed to provide a full implementation of the CAN protocol according to the CAN Specification Version 2.0B. The C_CAN controller allows to build powerful local networks with low-cost multiplex wiring by supporting distributed real-time control with a very high level of security. Problem: On the LPC43xx, there is an issue with the C_CAN controller AHB bus address decoding that applies to both C_CAN controllers. It affects the C_CAN controllers when peripherals on the same bus are used. Writes to the ADC, DAC, I2C, and I2S peripherals can update registers in the C_CAN controller. Specifically, writes to I2C0, MCPWM, and I2S can affect C_CAN1. Writes to I2C1, DAC, ADC0, and ADC1 can affect C_CAN0. The spurious C_CAN controller writes will occur at the address offset written to the other peripherals on the same bus. For example, a write to ADC0 CR register which is at offset 0 in the ADC, will result in the same value being written to the C_CAN0 CNTL register which is at offset 0 in the C_CAN controller. Writes to the C_CAN controller will not affect other peripherals. Work-around: Workarounds include: Using a different C_CAN peripheral. Peripherals I2C1, DAC, ADC0, and ADC1 can be used at the same time as C_CAN1 is active without any interference. The I2C0, MCPWM, and I2S peripherals can be used at the same time as C_CAN0 is active without any interference. Another workaround is to gate the register clock to the CAN peripheral in the CCU. This will prevent any writes to other peripherals from taking effect in the CAN peripheral. However, gating the CAN clock will prevent the CAN peripheral from operating and transmitting or receiving messages. This workaround is most useful if your application is modal and can switch between different modes such as an I2S mode and a CAN mode. Another workaround is to avoid writes to the peripherals while CAN is active. For example, the ADC could be configured to sample continuously or when triggered by a timer, before the CAN is configured. Afterwards, C_CAN0 can be used since the ADC will operate without requiring additional writes