+@ updates fceu "timestamp" variable
+@ loads cycles to reg, reg!=r1, trashes r1
+.macro FLUSH_TIMESTAMP reg
+ ldr r1, [REG_OP_TABLE, #OTOFFS_TIMESTAMP]
+ and \reg, REG_CYCLE, #0xff
+ add r1, r1, \reg
+ bic REG_CYCLE, REG_CYCLE, #0xff
+ str r1, [REG_OP_TABLE, #OTOFFS_TIMESTAMP]
+.endm
+