Z8FMC04100 ZILOG [Zilog, Inc.], Z8FMC04100 Datasheet - Page 266

• Manufacturer Part Number: Z8FMC04100
• Description: Z8 Encore-R Motor Control Flash MCUs
• Manufacturer: ZILOG [Zilog, Inc.]

244
Z8 Encore!
Product Specification
On-Chip Debugger
OCD Auto-Baud Detector/Generator
OCD Serial Errors
®
Motor Control Flash MCUs
Figure 44. OCD Data Format
To run over a range of baud rates (bits per second) with various system clock frequencies,
the On-Chip Debugger has an Auto-Baud Detector/Generator. After a reset, the OCD is
idle until it receives data. The OCD requires that the first character sent from the host is
the character
plus 7 data bits). The Auto-Baud Detector measures this period and sets the OCD Baud
Rate Generator accordingly.
The Auto-Baud Detector/Generator is clocked by the system clock. The minimum baud
rate is the system clock frequency divided by 512. The maximum recommended baud rate
is the system clock frequency divided by 8. Table 133 lists minimum and recommended
maximum baud rates for sample crystal frequencies.
Table 133. OCD Baud-Rate Limits
If the OCD receives a Serial Break (ten or more continuous bits Low) the Auto-Baud
Detector/Generator resets. The Auto-Baud Detector/Generator can then be reconfigured
by sending
character, the Auto-Baud Detector will remain reset.
The On-Chip Debugger can detect any of the following error conditions on the DBG pin:
•
•
ST = Start Bit
SP = Stop Bit
D0—D7 = Data Bits
Serial Break (a minimum of ten continuous bits Low)
Framing Error (received STOP bit is Low)
System Clock
Frequency
32.768 KHz
20.0 MHz
1.0 MHz
ST
80h
80h
. If the Auto-Baud Detector overflows while measuring the Auto-Baud
. The character
D0
D1
P R E L I M I N A R Y
Maximum Asynchronous
80h
Baud Rate (bits/s)
D2
contains eight continuous bits Low (one Start bit
125 K
2.5 M
4096
D3
D4
D5
Baud Rate (bits/s)
D6
Minimum
39.1 K
1960
64
D7
PS024604-1005
SP