1. Write a VHDL model for a 74HC192 synchronous 4-bit up/down counter. Ignore all timing data. Your code should contain a statement of the form process(DOWN, UP, CLR, LOADB)
2. Consider the following 8-bit bi-directional synchronous shift register with parallel load capability. The notation used to represent the input/output pins is explained below.
![2001_d3ee7e54-2fef-4bc1-bae1-e563166b144c.png](https://secure.tutorsglobe.com/CMSImages/2001_d3ee7e54-2fef-4bc1-bae1-e563166b144c.png)
The mode control inputs work as follows:
![735_0957e59d-49db-4e52-b330-d43cd7e9054a.png](https://secure.tutorsglobe.com/CMSImages/735_0957e59d-49db-4e52-b330-d43cd7e9054a.png)
(a) Write an entity description for this shift register.
(b) Write an architecture description of this shift register.
(c) Draw a block diagram illustrating how two of these can be connected to form a 16-bit cyclic shift register, which is controlled by signals L and R. If L = ‘1' and R = ‘0', then the 16-bit register is cycled left. If L = ‘0' and R = ‘1', the register is cycled right. If L = R = ‘1', the 16-bit register is loaded from X(15:0). If L = R = ‘0', the register is unchanged.
(d) Write an entity description for the module in part (c). (e) Write an architecture description using the module from parts (a) and (b).