TSC80251 TEMIC [TEMIC Semiconductors], TSC80251 Datasheet - Page 21

• Manufacturer Part Number: TSC80251
• Manufacturer: TEMIC [TEMIC Semiconductors]

Rev. C – May 7, 1999
3.4.1. Byte, Word and Dword Registers
Depending on its location in the register file, a register is addressable as a byte, a word, or a dword, as shown in the
right side of Figure 3.5. A register is named for its lowest numbered byte location. For instance:
Locations R0-R15 are addressable as bytes, words or dwords. Locations 16-31 are addressable only as words or dwords.
Locations 56-63 are addressable only as dwords. Registers are addressed only by the names shown in Figure 3.5. ,
except for the 32 registers that comprise the four banks of registers R0-R7, which can also be accessed as locations
00:0000h-00:001Fh in the memory space.
56
24
16
8
0
0
R4 is the byte register consisting of location 4.
WR4 is the word register consisting of registers 4 and 5.
DR4 is the dword register consisting of registers 4, 5, 6, and 7.
Locations 32-55 are Reserved
57
25
17
9
1
1
58
26
18
10
2
2
Register File
Figure 3.5. Register File in Byte, Word, and Dword Register Views
Banks 0-3
59
27
19
11
3
3
60
28
20
12
4
4
61
29
21
13
5
5
62
30
22
14
6
6
63
31
23
15
7
7
R8
R0
WR24
WR16
Note :
WR8
WR0
DR56 = DPX
R9 R10 R11 R12 R13 R14 R15
R1
DR24
DR16
DR8
DR0
R2
Byte Registers
R10 = B
R11 = A
Word Registers
Dword Registers
WR26
WR18
WR10
WR2
R3
R4
TSC80251
DR60 = SPX
WR28
WR20
WR12
WR4
R5
DR12
DR28
DR20
DR4
R6
WR14
WR30
WR22
WR6
R7
3.5