Power Signals
MSC8122 Technical Data, Rev. 13
Freescale Semiconductor
1-3
1.1 Power Signals
1.2 Clock Signals
1.3 Reset and Configuration Signals
Table 1-2.
Power and Ground Signal Inputs
Signal Name
Description
V
DD
Internal Logic Power
V
DD
dedicated for use with the device core. The voltage should be well-regulated and the input should be provided with
an extremely low impedance path to the V
DD
power rail.
Input/Output Power
This source supplies power for the I/O buffers. The user must provide adequate external decoupling capacitors.
V
DDH
V
CCSYN
System PLL Power
V
CC
dedicated for use with the system Phase Lock Loop (PLL). The voltage should be well-regulated and the input
should be provided with an extremely low impedance path to the V
CC
power rail.
System Ground
An isolated ground for the internal processing logic and I/O buffers. This connection must be tied externally to all chip
ground connections, except GND
SYN
. The user must provide adequate external decoupling capacitors.
System PLL Ground
Ground dedicated for system PLL use. The connection should be provided with an extremely low-impedance path to
ground.
GND
GND
SYN
Table 1-3.
Clock Signals
Signal Name
Type
Signal Description
CLKIN
Input
Clock In
Primary clock input to the MSC8122 PLL.
CLKOUT
Output
Clock Out
The bus clock.
Reserved
Input
Reserved. Pull down to ground.
Table 1-4.
Reset and Configuration Signals
Signal Name
Type
Signal Description
PORESET
Input
Power-On Reset
When asserted, this line causes the MSC8122 to enter power-on reset state.
RSTCONF
Input
Reset Configuration
Used during reset configuration sequence of the chip. A detailed explanation of its function is provided in
the
MSC8122 Reference Manual
. This signal is sampled upon deassertion of PORESET.
Note:
When PORESET is deasserted, the MSC8122 also samples the following signals:
BM[0–2]—Selects the boot mode.
MODCK[1–2]—Selects the clock configuration.
SWTE—Enables the software watchdog timer.
DSISYNC, DSI64, CNFGS, and CHIP_ID[0–3]—Configures the DSI.
Refer to
Table 1-5
for details on these signals.
HRESET
Input/Output
Hard Reset
When asserted as an input, this signal causes the MSC8122 to enter hard reset state. After the device
enters a hard reset state, it drives the signal as an open-drain output.
SRESET
Input/Output
Soft Reset
When asserted as an input, this signal causes the MSC8122 to enter soft reset state. After the device
enters a soft reset state, it drives the signal as an open-drain output.