参数资料
型号: S5933QE
厂商: APPLIEDMICRO INC
元件分类: 总线控制器
英文描述: PCI BUS CONTROLLER, PQFP160
封装: PLASTIC, QFP-160
文件页数: 52/176页
文件大小: 823K
代理商: S5933QE
3-158
PASS-THRU OVERVIEW
S5933
After the host reads all Base Address Registers in the
system (as every PCI device implements from one to
six), the PCI BIOS allocates memory and I/O space to
each Base Address region. The host then writes the
start address of each region back into the Base Ad-
dress Registers. The start address of a region is al-
ways an integer multiple of the region size. For
example, a 64 Kbyte memory region is always
mapped to begin on a 64K boundary in memory. It is
important to note that no PCI device can xbe abso-
lutely located in system memory or I/O space. All map-
ping is determined by the system, not the application.
Accessing a Pass-Thru Region
After the system is finished defining all Base Address
Regions within a system, each Base Address Register
contains a physical address. The application software
must now find the location in memory or I/O space of
its hardware. PCI systems provide BIOS or operating
system function calls for application software to find
particular devices on the PCI bus based on Vendor ID
and Device ID values. This allows application software
to access the device’s Configuration Registers.
The Base Address Register values in the S5933’s
Configuration Space may then be read and stored for
use by the program to access application hardware.
The value in the Base Address Registers is the
physical address of the first location of that Pass-
Thru region. Some processor architectures allow this
address to be used directly to access the PCI device.
For Intel Architecture systems, the physical address
must be changed into a Segment/Offset combination.
For Real Mode operation in an Intel Architecture sys-
tem (device mapped below 1 Mbyte in memory), creat-
ing a Segment/Offset pair is relatively simple. To
calculate a physical address, the CPU shifts the seg-
ment register 4 bits to the left and adds the offset
(resulting in a 20 bit physical address). The value in
the Base Address Register must be read and shifted 4
bits to the right. This is the segment value and should
be stored in one of the Segment registers. An offset of
zero (stored in SI, DI or another offset register) ac-
cesses the first location in the Pass-Thru region.
相关PDF资料
PDF描述
S6A0032 16 X 80 DOTS DOT MAT LCD DRVR AND DSPL CTLR, UUC138
S6A0069 16 X 40 DOTS DOT MAT LCD DRVR AND DSPL CTLR, UUC80
S6A0078 34 X 120 DOTS DOT MAT LCD DRVR AND DSPL CTLR, UUC183
S80296SA40 16-BIT, 40 MHz, MICROCONTROLLER, PQFP100
S80486-DX4-75-S-V-8-B 32-BIT, 75 MHz, MICROPROCESSOR, PQFP208
相关代理商/技术参数
参数描述
S5935 制造商:AMCC 制造商全称:Applied Micro Circuits Corporation 功能描述:PCI Product
S5935_07 制造商:AMCC 制造商全称:Applied Micro Circuits Corporation 功能描述:PCI Product
S59355QRC 制造商:AppliedMicro 功能描述:
S5935QF 制造商:AMCC 制造商全称:Applied Micro Circuits Corporation 功能描述:PCI Product
S5935QRC 制造商:AppliedMicro 功能描述:PCI Master Device 160-Pin PQFP