Table 973. Class/Protocol Relationship - STMicroelectronics SPC572L series Reference Manual

IEEE 1149.7 Compact JTAG Test Access Port Controller (CJTAG)
Class
T0 – T2
T3
T4
The CJTAG module implements T4 functionality and supports the Standard, Advanced, and
Control Protocols.
60.3.5.1 Standard Protocol
The Standard Protocol is the signaling defined by the IEEE 1149.1 standard. This protocol is
also used to implement TAP.7 commands using only the TCK(C) and TMS(C) signals in a
manner that does not require either TAP.7 controller instruction or data registers. The TAP.7
controller does not add bits to the scan paths of underlying technology. The Standard
Protocol can be used to manage the TAP.7 controller functionality independent of the
function associated with the availability of the TDI and TDO signals. The Standard Protocol
supports STL data transfers only when these signals are present and provide the 1149.1
functionality defined by the IEEE 1149.1 standard.
60.3.5.2 Advanced Protocol
The Advanced Protocol supports both STL data transfers and management of the TAP.7
controller functionality with both the 2-signal (narrow) and 4-signal (wide) configurations.
The Advanced Protocol serializes the TMS, TDI, and TDO information used with the
Standard Protocol using only the TCK(C) and TMS(C) signals. A number of additional scan
formats provide bit sequences optimized for specific use cases. Each of these additional
scan formats affects the TMSC signaling sequences.
60.3.5.3 Control Protocol
The Control Protocol uses Escape sequences to reset the TAP.7 controller, place a TAP.7
controller offline or online, and indicate End of Transmission (EOT) with the Advanced
Protocol. The characteristics of this protocol provide Hot-Connect-Protection by requiring a
preamble of alternating ones and zeroes preceding a selection escape when a TAP
controller is started up offline.
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Table 973. Class/protocol relationship

Standard
Mandatory
Mandatory
Mandatory
DocID027809 Rev 4
Protocol
Control
Optional
Mandatory
Mandatory
RM0400
Advanced
N/A
N/A
Mandatory