NXP Semiconductors i.MX 6Dual Reference Manual

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ERR009535Chip Errata for the i.MX 6Dual/6Quad and i.MX 6DualPlus/6QuadPlus, Rev. 6.1, 06/201694 NXP SemiconductorsDescription:According to the eCSPI specifications, when eCSPI is set to operate in the Slave mode(CHANNEL_MODE[x] = 0), the SS_CTL[x] bit controls the behavior of burst completion.In the Slave mode, the SS_CTL bit should control the behavior of SPI burst completion as follows:• 0—SPI burst completed when (BURST_LENGTH + 1) bits are received• 1—SPI burst completed when the SS input is negatedAlso, in BURST_LENGTH definition, it is stated “In the Slave mode, this field takes effect in SPItransfer only when SS_CTL is cleared.”However, the mode SS_CTL[x] = 1 is not functional in Slave mode. Currently, BURST_LENGTHalways defines the burst length.According to the SPI protocol, negation of SSB always causes completion of the burst. However,due to the above issue, the data is not sampled correctly in RxFIFO when{BURST_LENGTH+1}mod32 is not equal to {actual burst length}mod32.Therefore, setting the BURST_LENGTH parameter to a value greater than the actual burst doesnot resolve the issue.Projected Impact:Slave mode with unspecified burst length cannot be supported due to this issue. The burst lengthshould always be specified with the BURST_LENGTH parameter and the SS_CTL[x] should beset to zero.Workarounds:There is no workaround except for not using the SS_CTL[x] = 1 option in the Slave mode. Theaccurate burst length should always be specified using the BURST_LENGTH parameter.Proposed Solution:No fix scheduled.Linux BSP Status:Software workaround not implemented in Linux BSP. Functionality or mode of operation in whichthe erratum may manifest itself is not used.ERR009535 eCSPI: Burst completion by SS signal in slave mode is not functional