I have a design using several L6472 ICs. Everything seems to work fine except when I go to read the abs_pos register. For instance: if the position register is reading 0x00084AF and I command the driver to move the motor 400 half-steps (bi polar motor and half stepping) I get a full revolution of the motor but when I read the abs_pos register after the move it reads 0x00086BF. A change of 528. If I tell the driver to move another 400 half-steps in the same direction and then read the abs_reg again it reads 0x00087CF. A change of 272. It is odd that the sum of the differences is 800. Am I missing something basic here?
