Fujitsu F2MC-16LX MB90580 Series Hardware Manual

Also see for F2MC-16LX Series: User guide Application note Operation manual Hardware manual Hardware manual

14.4 OperationsMB90580 Series Chapter 14: 8/16-Bit PPG 205(8) Reload register write timingIn a mode other than 16-bit PPG mode, it is recommended to use a word transfer instruction to write datain reload registers PRLL and PRLH. If two byte transfer instructions are used to write a data item to theseregisters, a pulse of unexpected width may be output depending on the timing.Figure 14.4c Write timing chartAssume that PRLL is updated from A to C before point ¬ in the time chart above, and PRLH is updatedfrom B to D after point ¬. Since the PRL values at point ¬ are PRLL=C and PRLH=B, a pulse of L sidecount value C and H side count value B is output only once.Similarly, to write data in PRL of ch0 and ch1 in 16-bit PPG mode, use a long word transfer instruction, oruse word transfer instructions in the order of ch0 and then ch1. In this mode, the data is only temporarilywritten to ch0 PRL. Then, the data is actually written into ch0 PRL when the ch1 PRL is written to.In a mode other than 16-bit PPG mode, ch0 and ch1 PRL are written independently.Figure 14.4d PRL write operation block diagramPPG0B B C CA A D DC B¬ch0 PRL write datach0 write in a mode otherTemporary latchTransferred in synchronizationch1 PRL write datach0 PRLch1 writech1 PRLthan 16-bit PPG modewith ch1 write in 16-bitPPG mode