Ieee5 computing power

1.

32 bits are s (1 bit) + e (8 bits) + m (23 bits)

1, - 5 means - 101 = - 1.01x2 ^ 2
is negative, so s = 1
e = 2 + 127 = 129 means 1000 000 1
m = 01
- 5 should be expressed as
1100 0000 1010 0000
means c0a00000

2 -1.5 i.e. - 1.1
s = 1
e = 0 + 127 = 127 i.e. 0111111
m = 1
- 1.5 should be expressed as
1011111 11000000
i.e. bfc00000

extended data

floating point notation:

floating point notation is a known C / C + + compiler, which is expressed in accordance with IEEE floating point notation To do the operation. This structure is a scientific representation, which is represented by sign (+ or -), index and mantissa, and the base is determined as 2. So in IEEE floating-point notation, a floating-point number is the exponential power of the mantissa multiplied by 2 plus a sign

references

Network floating point notation

2. Media access is different. IEEE802.3 adopts CSMA / CD mode, which is called carrier sense multiple access control protocol with collision detection; IEEE802.4 adopts token bus, which is called token bus protocol; Ieee802.5 adopts token ring, which is called token ring protocol.

3.

The process is as follows:

5 = 101 (original code) = 1.01x2 ^ 2

for IEEE754 single precision floating-point number = (- 1) ^ s * (1. F) * 2 ^ (e-127)

for - 5

symbol bit: S = 1 (one bit)

mesocode: e = 127 + 2 = 1000 000 1 (8 digits)

mantissa: F = 010 0000 (23 digits)

In the definition of IEEE 754-2008, 32-bit base 2 format is officially called binary 32 format. This format is defined as single in IEEE 754-1985. It should be noted that in some earlier computer systems, there are other 4-byte floating-point number formats

the complement of a number is to invert the bit of the number, and then add 1 to the result. In the complement system, a negative number is represented by the complement of its corresponding positive number

4. The ieee802.5 standard defines the token ring MAC sublayer and physical layer specification
mainly as follows
1. Single token protocol 2. Priority bit 3. Monitoring station 4. Reservation indicator
ieee802.5 standard defines 25 kinds of cut-off access control frames to complete the ring maintenance function

5. IEEE802.3 (CSMA / CD access control) vs. ieee802.5 (token ring access control) we call the transmission form of Ethernet as broadcast, while token ring uses the specified form; broadcast belongs to the protocol of probabilistic form, that is, it can not guarantee that the workstation can obtain the ability to connect the network cable. Token ring is a deterministic protocol, which uses a set of rules to ensure that the workstation has the ability to connect the network cable. In the aspect of IEEE standard, Ethernet belongs to 802.3 standard, while token ring belongs to 802.5 standard: feature class item IEEE 802.3 IEEE 802.5 logical form bus single ring physical form star, bus star medium optical fiber, twisted pair, CSMA / CD token passing overload information single 1 (4 Mbps) or multiple (16 Mbps) maximum packet volume 1518 bytes 4500 (4 Mbps) 18000 (16 Mbps) node number 1024 260 node spacing 2.8m (minimum) 100m (maximum) maximum network distance 2.8km IEEE802.3 signal molation CSMA / CD type 10 base 5 10 base 2 1base 5 10 base t transmission speed 10 Mbps 1 Mbps 10 Mbps thick coaxial cable rg-11 thin coaxial cable rg-58 A / u unshielded twisted pair (UTP) network connection form bus (bus) star / bus length limit 500m / section 185m / section 2 4km 4km can be connected to a maximum of 5 segments, each segment can be connected to a maximum of 100 computers, 30 media access control CSMA / CD back to IEEE802.3 uses CSMA / CD as the communication media access method, the most common Ethernet is in line with this standard. The workstation on the network can freely access the line. When it needs to transmit data, it first monitors whether there is a signal transmitting on the network, which is carrier sense. If the network is busy, i.e. wait for a random period of time, and then try again. If there is still signal transmission, repeat the above action, that is multiple access. If it is sent out, you still have to monitor whether the data collides with other people's data. This action is called collision detection. The signal molation mode is back to the fundamental frequency mode: the digital signal is directly encoded by 0 and 1 and transmitted on the communication media through the tranceiver. It can only transmit one channel at a time, which is cheap and easy to install. Broadband mode: the digital signal through a high-frequency signal molation, converted into a higher frequency analog signal. FDM (frequency division multiplexing) is usually used to carry out multi-channel communication on one transmission medium. The advantages of Manchester coding back to this coding method are as follows: 1. The synchronization effect can be achieved by the change of bit order between 0 and 1 of the transmitted signal without additional synchronization sequence. This is called "self clocking". 2. The transmission line will not proce DC voltage component. 3. It is easy to detect transmission errors. Ieee802.5 the specifications of ieee802.5 are as follows: specifications ieee802.5 FSK (carrier frequency band) signal molation mode signal coding differential Manchester coding media access control mark bus transmission speed 4 Mbps 4, 16 Mbps adopts cable unshielded twisted pair network connection mode, and each section can connect up to 250 computers. In addition, there is an IEEE802.4 standard, which physically uses bus mode, but transmits data in the form of token passing. Like token ring, only the node that gets the token can send data, but once it gets the acknowledgement response from the receiving node, it has to give the token to the next node. In the network, there must be a mechanism to track which node will be the next to get the token. There will be a master role on the network. If the token is lost or cannot be transmitted for some reason, the master will first send a request to the whole network, and then announce to cancel the old token and issue a new one. It has the highest priority to obtain the token than any other node. However, compared with the star form of token ring, 802.4 still has its shortcomings. For example, the mart hub used in 802.5 has the ability to detect the node that is not working well, so that the token can be passed around it. At the same time, it will indicate which node has a problem, while 802.4 can not. reference: http://www.cpshs.hcc.e.tw/leson/net/new_ page_ 9.htm

6. How can you ask such a professional question here.....

7. Token ring network is a local area network based on ring network topology, as shown in Figure 1-12. Although it can be connected by star structure in physical composition, it still works in the form of ring in logic. Its communication transmission medium can be unshielded twisted pair, shielded twisted pair and optical fiber

the media access control mechanism of token ring network adopts the circulation method of distributed control mode. In token ring network, there is a token which is passed in turn along the ring bus between the computers of the network access nodes. The token is actually a special format frame, which does not contain information. It only controls the use of the channel to ensure that only one node can monopolize the channel at the same time. When all the nodes on the ring are idle, the token moves around the ring. The node computer can only send data frames after obtaining the token, so there will be no collision. Because the token is delivered in order on the ring, the access right is fair to all computers
there are two states of Token: idle and busy“ "Idle" means that the token is not occupied, that is, no computer is transmitting information in the network“ "Busy" indicates that the token has been occupied, that is, information is being transmitted in the network. The computer that wants to transfer data must first detect the "idle" token, set it to the "busy" state, and then transfer data after the token. When the data is received by the destination computer, the data is removed from the network and the token is reset to "idle". The disadvantage of token ring network is that it needs to maintain the token. Once the token is lost, it can not work. It needs to select a special node to monitor and manage the token

generally speaking, it is a loop... In the loop there seems to be an instruction in reality.. Having and having only one instruction... Everyone is waiting for that order.. In this way, there will be no conflict.

8. 16W />
2W:

9. IEEE
802.3
and token ring network, IEEE
802.5 belong to Ethernet standard, while LAN (local area network) uses Ethernet standard

10. IEEE is the abbreviation of Institute of electrical and electronics engineers, which is a very famous organization
IEEE 802 standard is the code of LAN technology standard formulated by IEEE. There are many sub codes in the code, which are used to distinguish different technology categories of LAN. For example, IEEE 802.3 represents Ethernet technology, IEEE 802.5 represents token ring technology, and IEEE 802.1 represents high-level interconnection and management protocol in LAN.