All i.MX6 SoCs have an OCOTP Controller with 4kbit fuses. The i.MX6SL is
an exception and has only 2kbit fuses.
In the TRM for the i.MX6DQ (IMX6QDRM - Rev 2, 06/2014) the fuses size is
described in chapter 46.1.1 with:
"32-bit word restricted program and read to 4Kbits of eFuse OTP(512x8)."
In the TRM for the i.MX6SL (IMX6SLRM - Rev 2, 06/2015) the fuses size is
described in chapter 34.1.1 with:
"32-bit word restricted program and read to 2 kbit of eFuse OTP(128x8)."
Since the Freescale Linux kernel OCOTP driver works with a fuses size of
2 kbit for the i.MX6SL, it looks like the TRM is wrong and the formula
to calculate the correct fuses size has to be 256x8.