Motorola DSP56009 User Manual page 62

Signal Descriptions
On-Chip Emulation (OnCE
Table 2-12 On-Chip Emulation Port Signals (Continued)
Signal Signal
Name Type
DSO Output
2-24
TM
) Port
State
during
Reset
Driven Debug Serial Output (DSO)—The DSO line
High provides the data contained in one of the OnCE
port controller registers as specified by the last
command received from the command controller.
The Most Significant Bit (MSB) of the data word is
always shifted out of the OnCE port first. Data is
clocked out of the OnCE port on the rising edge of
DSCK.
The DSO line also provides acknowledge pulses to
the external command controller. When the DSP
enters the Debug mode, the DSO line will be
pulsed low to indicate that the OnCE port is
waiting for commands. After receiving a read
command, the DSO line will be pulsed low to
indicate that the requested data is available and the
OnCE port is ready to receive clock pulses in order
to deliver the data. After receiving a write
command, the DSO line will be pulsed low to
indicate that the OnCE port is ready to receive the
data to be written; after the data is written, another
acknowledge pulse will be provided.
Note: During hardware reset and when idle, the DSO
line is held high.
DSP56009 User's Manual
Signal Description
MOTOROLA