EE 308
Homework #9
Due Apr. 4, 2001
For this homework you will be determing times for various things to happen in expanded mode. To do this, you will need to refer to the timing specifications for the HC12, which can be found on pages 478-479 of your Motorola M68HC12B Family Manual. You will also need the timing of the RAM chip, which can be found on pages 5-7 of the IDT 71V016 data sheet. Note that we are using the 12 ns version of the chip. Also, we are using a 12 ns Altera chip, so assume all delays through the Altera chip are 12 ns.
E
going low to R/W going low on a write cycle.
E going
low to a new address on AD15-0.
E going high until a new address appears on A7-0.
OEn, WEn, and
CEn should be low.
E going high to CEn
going low.
E going low to CEn
going high.
E going high to
AD15-0 changing from address mode to data mode.
E going low to
AD15-0 changing from data to address mode during a write cycle.
CEn going low the
the RAM chip putting data on the data bus on a read cycle.
CEn going high to
the RAM chip releasing the data bus.