In Figure 9.19, the 7-segment display unit for each digit incorporates a BCD-to-7- segment decoder; hence the microcontroller provides simultaneously a 4-bit BCD code for each digit that is to be displayed. Suppose that instead of using the decoder, each 7-segment unit has a 7-bit register with a control input Load, such that the seven data bits are loaded into the register when Load = 1. Each bit in the register drives one segment of the associated display unit. Figure P9.2 shows the register-display arrangement. Augment the programs in Figures 9.20 and 9.21 for use with this register-display circuit.

LO1