MMC2114 MOTOROLA [Motorola, Inc], MMC2114 Datasheet - Page 588

• Manufacturer Part Number: MMC2114
• Description: M CORE Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

JTAG Test Access Port and OnCE
22.14.4.1 OnCE Command Register
Advance Information
588
The OnCE Command Register (OCMR) is an 8-bit shift register that
receives its serial data from the TDI pin. This register corresponds to the
JTAG IR and is loaded when the update-IR TAP controller state is
entered. It holds the 8-bit commands shifted in during the shift-IR
controller state to be used as input for the OnCE decoder. The OCMR
contains fields for controlling access to a OnCE resource, as well as
controlling single-step operation, and exit from OnCE mode.
Although the OCMR is updated during the update-IR TAP controller
state, the corresponding resource is accessed in the DR scan sequence
of the TAP controller, and as such, the update-DR state must be
transitioned through in order for an access to occur. In addition, the
update-DR state must also be transitioned through in order for the
single-step and/or exit functionality to be performed, even though the
command appears to have no data resource requirement associated
with it.
R/W — Read/Write Bit
GO — Go Bit
When the GO bit is set, the device executes the instruction in the IR
Register in the CPUSCR. To execute the instruction, the processor
leaves debug mode, executes the instruction, and if the EX bit is
cleared, returns to debug mode immediately after executing the
instruction. The processor resumes normal operation if the EX bit is
set. The GO command is executed only if the operation is a read/write
to either the CPUSCR or to “no register selected.” Otherwise, the GO
Freescale Semiconductor, Inc.
Bit 7
R/W
For More Information On This Product,
1 = Read the data in the register specified by the RS field.
0 = Write the data associated with the command into the register
JTAG Test Access Port and OnCE
specified by the RS field.
Figure 22-9. OnCE Command Register (OCMR)
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G
6
EX
5
RS4
4
MMC2114 • MMC2113 • MMC2112 — Rev. 1.0
RS3
3
RS2
2
RS1
1
MOTOROLA
Bit 0
RS0