21164 Size Field - Samsung AlphaPC 164UX Technical Reference Manual

21164 Byte/Word PCI Space
Table 1–3 shows noncached 21164 addresses when byte/word support is enabled.
Table A–3 21164 Byte/Word Addressing
Instruction
LDQ
LDL
LDWU
LDBU
STQ
STL
STW
STB
A.4.1 21164 Size Field
Table A–4 shows the calculation of the 21164 size field.
Table A–4 21164 Byte/Word Translation Values
Size<38:37>
00
01
10
11
The following transactions use single data transfers on the PCI:
•
INT1 and INT2 read and write transactions
•
INT4 read transactions
The following transactions have multiple data transfers on the PCI:
•
INT4 write transactions
•
INT8 read and write transactions
System Address Space
A–14
addr_h
<38:37> <3>
00 INT8
01 addr_h<3:2>
10 addr_h<3:1>
11 addr_h<3:0>
00 INT4 Mask
01 INT4 Mask
10 addr_h<3:1>
11 addr_h<3:0>
Data Size
INT8 (Quadword — 8 bytes, 64 bits)
INT4 (Longword — 4 bytes, 32 bits)
INT2 (Word — 2 bytes, 16 bits)
INT1 (Byte — 1 byte, 8 bits)
int4_valid
<2> <1> <0>
— — —
— Undefined —
— — Undefined
— — —
— — —
— — —
— — Undefined
— — —