Figure 14-5. Conceptual 64-bit Peripheral ID
Table 14-2. Conceptual 64-Bit Peripheral ID Bit Descriptions
Field
Size Description
Location
JEP-106 CC code 4
Atmel continuation code: 0x0
PID4
JEP-106 ID code 7
Atmel device ID: 0x1F
PID1+PID2
4KB count
4
Indicates that the CoreSight component is a ROM: 0x0
PID4
RevAnd
4
Not used; read as 0
PID3
CUSMOD
4
Not used; read as 0
PID3
PARTNUM
12
Contains 0xCD0 to indicate that DSU is present
PID0+PID1
REVISION
4
DSU revision (starts at 0x0 and increments by 1 at both major
and minor revisions). Identifies DSU identification method
variants. If 0x0, this indicates that device identification can be
completed by reading the Device Identification register (DID)
PID3
For more information, refer to the ARM Debug Interface Version 5 Architecture Specification.
14.10.2. Chip Identification Method
The DSU DID register identifies the device by implementing the following information:
•
Processor identification
•
Product family identification
•
Product series identification
•
Device select
14.11. Functional Description
14.11.1. Principle of Operation
The DSU provides memory services such as CRC32 or MBIST that require almost the same interface.
Hence, the Address, Length and Data registers (ADDR, LENGTH, DATA) are shared. These shared
registers must be configured first; then a command can be issued by writing the Control register. When a
command is ongoing, other commands are discarded until the current operation is completed. Hence, the
user must wait for the STATUSA.DONE bit to be set prior to issuing another one.
Atmel SAM L22G / L22J / L22N [DATASHEET]
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