RM0444 Rev 5 1347/1390
RM0444 HDMI-CEC controller (CEC)
1364
39 HDMI-CEC controller (CEC)
39.1 Introduction
Consumer electronics control (CEC) is part of HDMI (high-definition multimedia interface)
standard as appendix supplement 1. It contains a protocol that provides high-level control
functions between various audiovisual products. CEC operates at low speeds, with
minimum processing and memory overhead.
The HDMI-CEC controller provides hardware support for this protocol.
39.2 HDMI-CEC controller main features
• Complies with HDMI-CEC v1.4 specification
• 32 kHz CEC kernel with 2 clock source options
– HSI RC oscillator with fixed prescaler (HSI/488)
– LSE oscillator
• Works in Stop mode for ultra-low-power applications
• Configurable signal-free time before start of transmission
– Automatic by hardware, according to CEC state and transmission history
– Fixed by software (7 timing options)
• Configurable peripheral address (OAR)
• Supports Listen mode
– Enables reception of CEC messages sent to destination address different from
OAR without interfering with the CEC line
• Configurable Rx-tolerance margin
– Standard tolerance
– Extended tolerance
• Receive-error detection
– Bit rising error (BRE), with optional stop of reception (BRESTP)
– Short bit period error (SBPE)
– Long bit period error (LBPE)
• Configurable error-bit generation
– on BRE detection (BREGEN)
– on LBPE detection (LBPEGEN)
– always generated on SBPE detection
• Transmission error detection (TXERR)
• Arbitration lost detection (ARBLST)
– with automatic transmission retry
• Transmission underrun detection (TXUDR)
• Reception overrun detection (RXOVR)