TMC2240 HSTRT+HEND limitation in datasheet appears to be off by one

Question

The TMC2240 datasheet states: 
 > The sum HSTRT + HEND must be &le;16. At a current setting of max. 30 (amplitude reduced to 240), the sum is not limited. 
 This value appears to come from the default peak sine wave current of 248, however 248 + 16/2 = 256. It seems odd that a maximum of 256 would be allowed rather than a maximum of 255 to fit in an 8-bit value (or 255.5 if it's 8+1-bit fixed point internally). So is this limit actually correct or should it be 14 or 15 instead?

BernhardDwersteg · Accepted Answer

Hi Liam, strictly speaking you are right, it would overrun for positive numbers. But the sine wave peak in positive range is 247, as it covers the 248 counts 0 to 247. This avoids an overflow when adding 16/2.)

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TMC2240 HSTRT+HEND limitation in datasheet appears to be off by one