s908ey16g2vfar Freescale Semiconductor, Inc, s908ey16g2vfar Datasheet - Page 244

• Manufacturer Part Number: s908ey16g2vfar
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Development Support
19.3.1.2 Forced Monitor Mode
If entering monitor mode without high voltage on IRQ, then PTA1, PTB3, and PTB4 pin requirements and
conditions are not in effect. This is to reduce circuit requirements when performing in-circuit programming.
If the reset vector is blank and monitor mode is entered without V
additional reset cycle after the initial power-on reset (POR). The MCU will initially come out of reset in user
mode. Internal circuitry monitors the reset vector fetches and will assert an internal reset if it detects the
reset vector is erased ($FFFF).
Once the MCU enters this mode any reset other than a POR will automatically force the MCU to come
back to the forced monitor mode. Exiting the forced monitor mode requires a POR. Pulling RST low will
244
Function
[Pin No.]
MON08
Monitor
Monitor
Normal
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
4. X = don’t care
5. RST column indicates the state of RST after the monitor entry.
6. 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.
V
V
V
V
IRQ
V
V
[6]
or
TST
TST
DD
DD
SS
SS
OSC1
V
V
RST
RST
V
V
V
V
[4]
V
or
TST
or
TST
DD
DD
DD
DD
Table 19-1. Monitor Mode Signal Requirements and Options
NC
NC
NC
NC
NC
NC
DD
Vector
$FFFF
(blank)
$FFFF
Reset
Not
11
13
15
—
X
1
3
5
7
9
MC68HC908EY16A • MC68HC908EY8A Data Sheet, Rev. 1
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
NC
PTA1
SSEL
[10]
X
0
0
0
MOD0
PTB4
[12]
Selection
X
X
X
1
Mode
MOD1
PTB3
[14]
0
X
X
X
OFF Disabled
OFF Disabled
ICG
ON
ON
—
TST
Disabled
Enabled
on IRQ, the MCU will see an
COP
—
External
9.8304
9.8304
Clock
OSC1
MHz
MHz
[13]
—
—
Communication
Freescale Semiconductor
2.45 MHz
Nominal
Nominal
1.6 MHz
Speed
2.4576
2.4576
MHz
MHz
f
—
OP
SS
Nominal
Baud
case.
Rate
9600
9600
9600
—
X