Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
Offset Field Name Definition
Byte 16 Data Bit Length The size in bits of the smallest transfer unit. _LEN
Byte 17 Phase The phase (CPHA) of the clock pulse on which to capture data
(the other being used to transmit). _PHA
0 – First phase
1 – Second phase
Byte 18 Polarity The polarity of the clock (CPOL). This value indicates if the
clock is low or high during the first phase (see Phase above).
_POL
0 –Start Low
1 –Start High
Byte 19 Device Selection, bits [7:0] Lower eight bits of the device selection value. This value is
specific to the device and may refer to a chip-select line, GPIO
line or other line selection mechanism. _ADR[7:0]
Byte 20 Device Selection, bits
[15:8]
Upper eight bits of the device selection value. This value is
specific to the device and may refer to a chip-select line, GPIO
line or other line selection mechanism. _ADR[15:8]
Byte 21 Vendor Defined Data (Optional) Data specific to the controller device supplied by a
vendor. The number of bytes in this field is Type Data Length
– 9.
… … (Optional) Additional vendor supplied data.
String
Resource Source (Length
= L)
Name of the serial bus controller device to which this
connection descriptor applies. The name can be a fully
qualified path, a relative path, or a simple name segment that
utilizes the namespace search rules.
6.4.3.8.2.3 UART Serial Bus Connection Resource Descriptor
Table 6-222 UART Serial Bus Connection Descriptor
Offset Field Name Definition
Byte 0 Serial Bus Connection
Descriptor
Value = 0x8E (10001110B) – Type = 1, Large item name =
0x0E
Byte 1 Length, bits[7:0] Variable length, minimum value = 0x13 + L (17 + Resource
Source string length)
Byte 2 Length, bits[15:8] Variable length, minimum value = 0x00
Byte 3 Revision ID Indicates the revision of the Serial Bus Connection Descriptor.
This value is 1.
Byte 4 Resource Source Index Reserved (must be 0)
Byte 5 Serial Bus Type Serial Bus Type value must be 3 for UART
378 April, 2015 Version 6.0