MSC8144E Reference Manual, Rev. 3
25-12
Freescale
Semiconductor
Debugging, Profiling, and Performance Monitoring
25.1.8 Reading/Writing OCE Registers Through JTAG
An external host can read or write almost every OCE register through the JTAG interface by
performing the following steps:
1.
Execute the CHOOSE_ONCE command in the JTAG.
2.
Send the data showing which OCE module is chosen. This command enables the JTAG
to manage multiple OCE modules in a device.
3.
Execute the ENABLE_ONCE command in the JTAG.
4.
Write the OCE command into the ECR; that is, enter the JTAG TAP state machine into
the
SHIFT
-
DR
state and then give the required command on the
TDI
input signal.
After the command is shifted in, the JTAG TAP state machine must enter the
UPDATE
-
DR
state.
The data shifted via the
TDI
is sampled into the ECR. If, for example, the command written into
the ECR is Write EDCA0_CTRL, then the host must again enter the JTAG into
SHIFT
-
DR
and
shift the required data, which is to be written into the EDCA0_CTRL, via
TDI
. If the command is
read some register, then the DR chain must be passed again and the contents of the register are
shifted out through the
TDO
output signal. When JTAG shifts data to the OCE module, the lsb of
the data is shifted first. See Figure 25-7.
Figure 25-7. Reading and Writing OCE Registers Via the JTAG TAP
OCE module is connected to the TDO.
OCE module is ready to get command in ECR.
Write command into ECR register via shift-dr or update-dr
Execute CHOOSE_ONCE instruction in JTAG
.
Execute ENABLE_ONCE instruction in JTAG
The chosen register is selected.
Write/read data into the chosen register via shift-dr or update-dr.
The chosen register is written/read.
Bits 0–6 = address of the chosen register.
Bits 7–8 = 00
Bit 9 = 0 for a write command, and 1 for a read command
Write JTAG data to choose the OCE module
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...