Repeat Problem 12-11 if the address inputs are changed 70 ns prior to the TRANSFER pulse.

Data from Problem 12-11

Figure 12-40 shows how data from a ROM can be transferred to an external register. The ROM has the following timing parameters: t_ACC = 250 ns and t_OE = 120 ns. Assume that the new address inputs have been applied to the ROM 500 ns before the occurrence of the TRANSFER pulse. Determine the minimum duration of the TRANSFER pulse for reliable transfer of data.

Figure 12-40

A7 A6 A5 A4 A3 A A Ao Transfer CS U D7 De Ds D4 ROM 256 x 8 D OE D D Do D De D5 D4 Eight-bit D3 register D 74ALS273 D Do CLK [ILL Q7 Q3 Q Q