s908ey8ad4cfjer Freescale Semiconductor, Inc, s908ey8ad4cfjer Datasheet - Page 234

• Manufacturer Part Number: s908ey8ad4cfjer
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Development Support
19.3.1.2 Forced Monitor Mode
If entering monitor mode without high voltage on IRQ, then all port B pin requirements and conditions are
not in effect. This is to reduce circuit requirements when performing in-circuit programming.
With V
bus frequency is automatically set to the external frequency divided by four.
234
Function
[Pin No.]
MON08
Normal
Monitor
Monitor
Forced
1. PTA0 must have a pullup resistor to V
2. Communication speed in the table is an example to obtain a baud rate of 9600 except the forced monitor IRQ = V
3. External clock is a 9.8304 MHz canned oscillator on OSC1.
4. X = don’t care
5. MON08 pin refers to P&E Microcomputer Systems’ MON08-Cyclone 2 by 8-pin connector.
Mode
User
Baud rate using external oscillator is bus frequency / 256.
DD
on IRQ, an external oscillator of 9.8034 MHz is required for a baud rate of 9600, as the internal
V
V
IRQ
V
V
V
V
[6]
TST
or
TST
DD
SS
DD
SS
If the reset vector is blank and monitor mode is entered, the chip will see an
additional reset cycle after the initial power-on reset (POR). Once the reset
vector has been programmed, the traditional method of applying a voltage,
V
OSC1
TST
V
V
RST
RST
V
V
V
V
[4]
V
or
TST
or
TST
DD
DD
DD
DD
NC
NC
NC
NC
NC
NC
DD
, to IRQ must be used to enter monitor mode.
Table 19-1. Monitor Mode Signal Requirements and Options
Vector
(blank)
Reset
$FF
$FF
Not
11
13
15
—
X
1
3
5
7
9
MC68HC908EY16 • MC68HC908EY8 Data Sheet, Rev. 10
Communication
PTA0
COM
[8]
10
12
14
16
X
1
1
1
2
4
6
8
DD
Serial
in monitor mode.
GND
RST
IRQ
PTA0
PTA1
PTB3
PTB4
N.C.
PTA1
SSEL
[10]
X
0
0
0
MOD0
PTB4
[12]
NOTE
X
X
X
Selection
1
Mode
MOD1
PTB3
[14]
X
X
X
0
OFF Disabled
OFF Disabled
ICG
ON
CN
—
Disabled
Enabled
COP
—
External
9.8304
9.8304
Clock
OSC1
MHz
MHz
[13]
—
—
Communication
Freescale Semiconductor
Frequency
Nominal
1.6 MHz
Nominal
1.6 MHz
Speed
2.4576
2.4576
MHz
MHz
Bus
—
SS
Nominal
Baud
case.
9600
9600
6300
Rate
—
X