Homework 4
UCR EE/CS120B: Introduction to Embedded Systems
Fall Quarter 2004, Lecturer Brian Grattan

Due Tuesday, Nov. 16 at 8PM via web turnin in .txt or .pdf format.

Name:__________ANSWERS______________  

UCR ID#:________________________

1. (4 points) Fill in the blank with the type of memory described.  Only use memory types listed in Figure 5.2 of Embedded System Design:
a. Type of memory used in nearly all on-chip caches:
SRAM
b. Type of memory which is programmed using a programmer which basically blows fuses to program it:
OTP
c. Type of memory that is written when the chip is fabricated and never again:
MASK-PROGRAMMED
d. Type of memory that is erased using UV light:
EPROM

2. (8 points) Write the VHDL (entity and architecture) that would be needed to create the component “1X2 decoder” in the bottom left of figure 5.10 in the ESD book.  You will have two inputs (Am and enable) and two outputs (B1, going to the upper ROM and B2, going to the lower ROM).

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entity DECODER is
  port (
    Am     : in std_logic;
    ENABLE : in std_logic;
    B1     : out std_logic;
    B2     : out std_logic);
end DECODER;

architecture RTL of DECODER is

begin

  B1 <= '1' when (ENABLE = '1' and Am = '0') else '0';
  B2 <= '1' when (ENABLE = '1' and Am = '1') else '0';

end RTL;

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3. (6 points) Find the datasheet for the CY7C1011CV33  from Cypress Semiconductor.  Answer the following questions regarding this part:
a. What type of memory is this?
SRAM
b. How many bits can this memory store?
2097152 (131,072 * 16)
c. Is this memory synchronous or asynchronous?
ASYNCHRONOUS
d. How wide is a data word for this memory?
16 BITS
e. How many bits do you need for the address for this memory?
17 BITS
f. Describe what you do to put this memory in it’s low power mode. 
SET CE' HIGH

4. (4 points) If you have a two-way set associative cache that has 1024 cache lines (or blocks) and the block size is four data words for each set, what would the tag, index  and offset be when the main processor requests the data at location 0xABCDEF?  Give you answer in binary.
TAG    = 101010111100
INDEX  = 1101111011
OFFSET = 11