Technical data

Analog Integrated Circuit Device Data
54 Freescale Semiconductor
908E621
TYPICAL APPLICATIONS
PCB level programming
If the IC is soldered onto the pcb board, its typically not
possible to separately power the MCU with +5V. The whole
system has to be powered up providing V
SUP
(see
Figure 31)..
Figure 31. Normal Monitor Mode Circuit
Table 22 summarizes the possible configurations and the
necessary setups.
MM908E621
RST_A
RST
IRQ_A
IRQ VSSA/VREFL
VDDA/VREFH
EVDD
VDD
EVSS
VSS
VSUP[1:8]
GND[1:4]
4.7µF100nF
PTC4/OSC1
PTB3/AD3
PTB4/AD4
PTA0/KBD0
PTA1/KBD1
TESTMODE
MAX232
10k
RS232
DB-9
1
3
C1+
C1-
4
5
C2+
C2-
7
8
2
3
5
V
CC
GND
16
15
2
V+
V-
6
1µF
+
1µF
+
+
1µF
1µF
+
+
1µF
2
1
3
65
4
74HC125
74HC125
9.8304MHz CLOCK
V
DD
V
DD
DATA
CLK
V
DD
10k
10k
10k
10k
V
DD
V
TST
V
SUP
47µF
+
100nF
10
9
T2
OUT
R2
IN
T2
IN
R2
OUT
Table 22. Monitor Mode Signal Requirements and Options
Mode IRQ RST
TESTMODE
Reset
Vector
Serial
Communication
Mode
Selection
ICG COP
Normal
Request
Time-out
Communication Speed
PTA0
PTA1 PTB3 PTB4
External
Clock
Bus
Frequency
Baud
Rate
Normal
Monitor
V
TST
V
DD
1 X 1 0 0 1 OFF disabled disabled
9.8304
MHz
2.4576
MHz
9600
Forced
Monitor
V
DD
V
DD
1
$FFFF
(blank)
10XX
OFF disabled disabled
9.8304
MHz
2.4576
MHz
9600
GND ON disabled disabled —
Nominal
1.6MHz
Nominal
6300
User V
DD
V
DD
0
not $FFFF
(not blank)
X X X X ON enabled enabled —
Nominal
1.6MHz
Nominal
6300
Notes
1. PTA0 must have a pullup resistor to V
DD
in monitor mode
2. External clock is a 4.9152MHz, 9.8304MHz or 19.6608MHz canned oscillator on OCS1
3. Communication speed with external clock is depending on external clock value. Baud rate is bus frequency / 256
4. X = don’t care
5. V
TST
is a high voltage V
DD
+3.5V ≤ V
TST
≤ V
DD
+4.5V