Hdmi-Cec Advanced Features - ST STM32F100 Series Application Note

High-definition multimedia interface, consumer electronics control (HDMI-CEC)
1.5.2

HDMI-CEC advanced features

The STM32 HDMI-CEC controller provides an easy platform to build CEC firmware
applications:
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dedicated address register containing up to 15 CEC device addresses
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Programmable high-resolution prescaler (14 bit) to obtain a 50 µs time base (HDMI
specification resolution)
● advanced arbitration mechanism using SFT (signal free time) and header arbitration
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dedicated transmission and reception flags (TBTRF and RBTF) with interrupt capability
● error handling in a single dedicated register: bit timing errors, bit period errors,
message errors and error bit generation
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error-free mode to allow safe communication with non-tolerant CEC devices. This
mode can be selected using a dedicated configuration bit.
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Rx digital filtering
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CEC controller built around a flexible state machine to ensure safe communication,
switching between the Tx and Rx modes, and easy error handling. There are 6 states:
Disabled, Idle, RX, TX, RX_ERROR and TX_ERROR. Please refer to the reference
manual (RM0041) available from www.st.com for more details.
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Wakeup-from-Stop source, with no data loss: the CEC line can be used as a wakeup
event from the Stop mode. The STM32 Wakeup system is fast enough to ensure that
there is no CEC data loss. CEC data received when the system is in the Stop mode
cause the system to wake up from the low power mode, and in so doing, allow the CEC
peripheral to easily retrieve them.
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Tx block transfer finished error (TBTFE)
Line error (LINE)
Block acknowledge error (ACKE)
Start bit error (SBE)
Rx block transfer finished error (RTBFE)
Bit period error (BPE)
Bit timing error (BTE)
Doc ID 16896 Rev 2
AN3127