5. (10%) The following figure shows Timero block diagram. The 8-bit register TMROH acts as a buffer between the TMRO high byte and the internal data bus. Explain why PIC18 needs this buffer scheme. Set interrupt flag bit TMROEF on averflow FOSCM Sync with internal clocks TMROL TMRO high byte TOCKIpin Programmable Prescaler 0 TOCS TOSE 12 Toy delay) Read TMROL Write TMROL PSA TOPS2, TOPS1.TOPSO TMROH Data bus Figure 8.1b Timero block diagram in 16-bit mode (redraw with permission of Microchip)