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reference:add-ons:pcam-5c:reference-manual [2020/03/27 20:36]
Arthur Brown [Features]
reference:add-ons:pcam-5c:reference-manual [2020/05/19 08:59] (current)
Elod Gyorgy [Serial Camera Control Bus (SCCB)] Better address format spec.
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 The SCCB on the Pcam 5C is a two-pin bus used to access the control registers for the OV5640 image sensor. The bus behaves the same way as an I2C bus, and can be treated exactly the same. This means it can be controlled using existing I2C IP cores or RTL. For a more complete description of how an I2C bus works, see the [[learn:​fundamentals:​communication-protocols:​i2c:​start|I2C Fundamentals Guide]]. The SCCB on the Pcam 5C is a two-pin bus used to access the control registers for the OV5640 image sensor. The bus behaves the same way as an I2C bus, and can be treated exactly the same. This means it can be controlled using existing I2C IP cores or RTL. For a more complete description of how an I2C bus works, see the [[learn:​fundamentals:​communication-protocols:​i2c:​start|I2C Fundamentals Guide]].
  
-It is expected that the host provide 1.5 KOhm pull-up resistors on both SCL and SDA. The attached host drives the clock (SCL) and behaves as the master on the bus. The OV5640 acts as a slave at the I2C address ​0x78. +It is expected that the host provide 1.5 KOhm pull-up resistors on both SCL and SDA. The attached host drives the clock (SCL) and behaves as the master on the bus. The OV5640 acts as a slave at the I2C addresses ​0x78/0x79, or in 7-bit format 0b111100.
  
 The register map accessed with the SCCB consists of 8-bit registers organized in a 16-bit address space. The details of how register read and write transactions occur are detailed in proprietary documentation that is available from OmniVision. Most users should not need to fully understand how the SCCB transactions occur, and can instead rely on the libraries included with the Pcam 5C demo that use the Zynq I2C hardware to properly read and write the OV5640 registers. The register map accessed with the SCCB consists of 8-bit registers organized in a 16-bit address space. The details of how register read and write transactions occur are detailed in proprietary documentation that is available from OmniVision. Most users should not need to fully understand how the SCCB transactions occur, and can instead rely on the libraries included with the Pcam 5C demo that use the Zynq I2C hardware to properly read and write the OV5640 registers.