I. Introduction
Then last updated textbook is an integral principle moon Tang Fei teacher's computer the second edition, the third part of chapter exercises are recorded
Second, the title
3.14 clock frequency of the bus lines is 8MHZ, a bus cycle is one clock cycle. If a bus cycle parallel transfer 16-bit data bus bandwidth ask is how much?
standard answer:
1) by the clock frequency of 8MHz, 16-bit data bits is available,
the bus bandwidth is 8 × 16 = 128 Mbps
3.15 in a 32-bit bus system, the bus frequency clock of 66MHZ is, assuming the shortest transmission cycle is four clock cycles the bus, the maximum data transfer rate of the bus again calculated. If you want to increase the data transfer rate, what measures can be taken?
standard answer:
1) by the bus transfer period 4/66 M seconds, to give the maximum rate of data transfer bus 32 / (4/66) = 528 Mbps
2) To increase the data transfer rate, the bus clock frequency can be increased, increasing the bus width or reduce the number of clock cycles of the bus transfer
3.16 asynchronous transmission system, the character format is: 1 start bit, 8 data bits, 1 parity bit, two stop bits 120 characters if a transmission request of requesting to transfer baud rate and bit rate.?
standard answer:
1) The meaning of the questions, a character with a 1 + 2 + 8 + 1 = 12,
then transferred to 120 characters per second, the baud rate is 12 is 120 = 1440bps, a bit rate of 8 120 = 960bps
notes:
1) a byte Byet = 8bit, so 1Bps = 8bps, 1MBps = 8Mbps, so the results can be simplified to 3.15 16MBps
Two Calculation Method 2) bus bandwidth
first: bandwidth = number of data bits × clock frequency
second: bandwidth = number of data bits / bus transmission cycle , transmission period = n × bus clock cycle, clock cycle = 1 / clock frequency
where n is the number of a predetermined transmission period corresponding to the title of the bus clock cycles, this method is also applicable to the data transfer rate is calculated
3) Method to increase the transmission rate
in accordance with formula (bandwidth calculation method of the second) data transfer rate, it is apparent, it can increase the number of clocks by the three bus clock frequency increase or decrease the bus width of the bus transfer cycle method.
4) The baud rate and the bit rate
baud rate of transmission of binary data bits per unit time
the number of bits per unit time transmitted bit rate of the binary data is valid
