In this technique we don't take the global maximum value, but the first maximum value that is above a certain threshold.
Use of depth weighting during production of rotating cines of MIP images can avoid the problem of difficulty of distinguishing right from left, and clockwise vs anti-clockwise rotation.Īn easy improvement to MIP is Local maximum intensity projection. However, since the projection is orthographic the viewer cannot distinguish between left or right, front or back and even if the object is rotating clockwise or anti-clockwise. This helps the viewer's perception to find the relative 3D positions of the object components. To improve the sense of 3D, animations are usually rendered of several MIP frames in which the viewpoint is slightly changed from one to the other, thus creating the illusion of rotation.
#BEQ MIPS MAXIMUM JUMMP DISTANCE PC#
If the opcode is such that a jump is to be executed then the top-right mux selects this new concatenated PC value and the next instruction to be fetched will be at the new address.Īctually, the PC is already incremented by 4, or one instruction, before being concatenated.This technique is computationally fast, but the 2D results do not provide a good sense of depth of the original data. This is a direct result of MIPS being word addressed (32 bits = 4 bytes = 1 MIPS word) rather than byte addressed, so the double left shift allows us to address 2^28, or 268,435,456 (256 MiB), instruction words within the range of the 4 most significant bits of the PC. As you can see from the picture above, the lower 26 bits from the instruction are shifted left twice and concatenated with the upper 4 bits already contained in the Program Counter (PC). The opcode is conitained in bits 31 to 26, shown feeding into the Control module. These bits are used by the control module in the datapath to determine what control signals to assert to facilitate execution of the instruction. So, 26 bits left shifted by two gives a relative address boundary of \$2^ bytes\$ is \$256 MiB\$, or \$256*1024^2\$.Īctually, the first 6 bits of the instruction are the opcode. Take the top 4 bits of the PC, concatenate that with the 26 bits that make up the target, and concatenate that with 00. This is how the address for pseudo-direct addressing is computed. | oooo oo | tt tttt tttt tttt tttt tttt tttt |Ģ6 bits are used for the target. Instead, we can do pseudo-direct addressing. However, MIPS uses 6 bits for the opcode, so there's still not enough bits to do true direct addressing. In theory, you only need 30 bits to specify the address of an instruction in memory. However, since MIPS instructions are 32 bits, we can't do that.
#BEQ MIPS MAXIMUM JUMMP DISTANCE 32 BIT#
The link gave also has the answer mid-page: Pseudo-Direct Addressingĭirect addressing means specifying a complete 32 bit address in the instruction itself. That way, they're not encoded in the answer explains it quite thoroughly, although I like the semantics of "word-aligned" more, than "word-addressed". The MIPS requires it's instructions to be 4-byte (word) aligned - i.e. Addressing in most CPU cores I know works on a per-byte basis.
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