Question about Ticks, Tocks, Sequential Logic, and the CPU compare file

[intelli78]

Let's look at the first 5 lines of the CPU compare file:

|time| inM  |  instruction   |reset| outM  |writeM |addre| pc  |DRegiste|
|0+  |     0|0011000000111001|  0  |*******|   0   |    0|    0|      0 |
|1   |     0|0011000000111001|  0  |*******|   0   |12345|    1|      0 |
|1+  |     0|1110110000010000|  0  |*******|   0   |12345|    1|  12345 |
|2   |     0|1110110000010000|  0  |*******|   0   |12345|    2|  12345 |

The D Register is a sequential chip, right? So why isn't its value 0 at t=1+, and only 12345 at t=2? I thought that logic only propagated on the tock.

I must be misunderstanding something, but I'm not sure what. Can anyone explain?

[ybakos]

In Hack, values latch on the rising edge of the clock cycle, which you will probably feel as the "tick".

The important thing about sequential chips is that values latch and then propogate in a manner that is separated by a full clock cycle.

[intelli78]

Thank you for the reply. I had misunderstood the sticky in this forum, but you've cleared it up. :)