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OCR GCSE(9-1) IN COMPUTER SCIENCE EXAM
LATEST WITH ACTUAL QUESTIONS AND
CORRECT VERIFIED ANSWERS ALREADY
GRADED A+ 100%GUARANTEED PASS!
what is the purpose of the CPU? - .....ANSWER ...✔✔
to process data by following the fetch-decode-execute
cycle, it's incharge of searching, sorting, calculating and
decision making
what happens at the fetch stage? - .....ANSWER
...✔✔ the CPU fetches data and instructions from
RAM and then stores them in it's own temporary memory
called registers
what happens at the decode stage? - .....ANSWER
...✔✔ the CPU understands what the instructions
mean, the CPU decodes the instructions and gets to the
next step
what happens at the execute stage? - .....ANSWER
...✔✔ the CPU carries out the instructions on the data
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define bus - .....ANSWER ...✔✔ information travels
along a bus from one part of the CPU to another
define address bus - .....ANSWER ...✔✔ a one way
bus that requires data from an address in memory
define data bus - .....ANSWER ...✔✔ moves data in
both directions as data is both read and written to
memory
define control unit - .....ANSWER ...✔✔ responsible
for timing on the CPU, uses the clock to ensure
operations happen in the correct sequence
define arithmetic logic unit - .....ANSWER ...✔✔ does
all arithmetic calculations and logical operations
define registers - .....ANSWER ...✔✔ Small temporary
storage spaces inside the CPU
define accumulator - .....ANSWER ...✔✔ stores the
results from the ALU temporarily until they're written to
memory
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define program counter - .....ANSWER ...✔✔ stores
the memory address of the next instruction, is
incremented by 1 at each new cycle
define instruction register - .....ANSWER ...✔✔ current
instruction is stored in this register
define memory address register - .....ANSWER ...✔✔
stores the memory address of the current instruction
being executed
define memory data register - .....ANSWER ...✔✔
stores the data that was read/written to memory
what is the function of the ALU? - .....ANSWER ...✔✔
performs basic arithmetic operations (addition,
subtraction, multiplication, and dividion) and logical
operations (AND, OR, NOT).
what is the function of the control unit? - .....ANSWER
...✔✔ manages and monitors hardware, manages the
input and output signals, uses clock signals to synchronise
the running of the fetch-decode-execute cycle
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what is the function of the cache? - .....ANSWER ...✔✔
a small amount of storage that temporarily holds
instructions that the CPU is likely to reuse, it's close to the
CPU and so is fast to access
what are the 3 factors affecting CPU performance? -
.....ANSWER ...✔✔ clock speed, cache size, number of
cores
How does clock speed affect CPU performance? -
.....ANSWER ...✔✔ the speed of the f-d-e cycle is
determined by the CPU's clock chip, the clock speed is
measured in hertz (cycles per second), the greater the
clock speed, the more instructions are processed per
second
what's the issue with increasing clock speed? -
.....ANSWER ...✔✔ the CPU can overheat
(overclocking), so you need to use heat syncs
How does cache size affect the performance of the
CPU? - .....ANSWER ...✔✔ if the cache is larger it's
more likely the next required instruction has already
OCR GCSE(9-1) IN COMPUTER SCIENCE EXAM
LATEST WITH ACTUAL QUESTIONS AND
CORRECT VERIFIED ANSWERS ALREADY
GRADED A+ 100%GUARANTEED PASS!
what is the purpose of the CPU? - .....ANSWER ...✔✔
to process data by following the fetch-decode-execute
cycle, it's incharge of searching, sorting, calculating and
decision making
what happens at the fetch stage? - .....ANSWER
...✔✔ the CPU fetches data and instructions from
RAM and then stores them in it's own temporary memory
called registers
what happens at the decode stage? - .....ANSWER
...✔✔ the CPU understands what the instructions
mean, the CPU decodes the instructions and gets to the
next step
what happens at the execute stage? - .....ANSWER
...✔✔ the CPU carries out the instructions on the data
,2|Page
define bus - .....ANSWER ...✔✔ information travels
along a bus from one part of the CPU to another
define address bus - .....ANSWER ...✔✔ a one way
bus that requires data from an address in memory
define data bus - .....ANSWER ...✔✔ moves data in
both directions as data is both read and written to
memory
define control unit - .....ANSWER ...✔✔ responsible
for timing on the CPU, uses the clock to ensure
operations happen in the correct sequence
define arithmetic logic unit - .....ANSWER ...✔✔ does
all arithmetic calculations and logical operations
define registers - .....ANSWER ...✔✔ Small temporary
storage spaces inside the CPU
define accumulator - .....ANSWER ...✔✔ stores the
results from the ALU temporarily until they're written to
memory
,3|Page
define program counter - .....ANSWER ...✔✔ stores
the memory address of the next instruction, is
incremented by 1 at each new cycle
define instruction register - .....ANSWER ...✔✔ current
instruction is stored in this register
define memory address register - .....ANSWER ...✔✔
stores the memory address of the current instruction
being executed
define memory data register - .....ANSWER ...✔✔
stores the data that was read/written to memory
what is the function of the ALU? - .....ANSWER ...✔✔
performs basic arithmetic operations (addition,
subtraction, multiplication, and dividion) and logical
operations (AND, OR, NOT).
what is the function of the control unit? - .....ANSWER
...✔✔ manages and monitors hardware, manages the
input and output signals, uses clock signals to synchronise
the running of the fetch-decode-execute cycle
, 4|Page
what is the function of the cache? - .....ANSWER ...✔✔
a small amount of storage that temporarily holds
instructions that the CPU is likely to reuse, it's close to the
CPU and so is fast to access
what are the 3 factors affecting CPU performance? -
.....ANSWER ...✔✔ clock speed, cache size, number of
cores
How does clock speed affect CPU performance? -
.....ANSWER ...✔✔ the speed of the f-d-e cycle is
determined by the CPU's clock chip, the clock speed is
measured in hertz (cycles per second), the greater the
clock speed, the more instructions are processed per
second
what's the issue with increasing clock speed? -
.....ANSWER ...✔✔ the CPU can overheat
(overclocking), so you need to use heat syncs
How does cache size affect the performance of the
CPU? - .....ANSWER ...✔✔ if the cache is larger it's
more likely the next required instruction has already
