mc68hc916y3 Freescale Semiconductor, Inc, mc68hc916y3 Datasheet - Page 159

• Manufacturer Part Number: mc68hc916y3
• Description: Mc68hc16y3 16 Bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

5.7.5 Pin State During Reset
5.7.5.1 Reset States of SCIM2 Pins
MC68HC16Y3/916Y3
USER’S MANUAL
It is important to keep the distinction between pin function and pin electrical state clear.
Although control register values and mode select inputs determine pin function, a pin
driver can be active, inactive or in high-impedance state while reset occurs. During
power-on reset, pin state is subject to the constraints discussed in 5.7.7 Power-On Re-
set.
Generally, while RESET is asserted, SCIM2 pins either go to an inactive high-
impedance state or are driven to their inactive states. After RESET is released, mode
selection occurs, and reset exception processing begins. Pins configured as inputs
must be driven to the desired active state. Pull-up or pull-down circuitry may be
necessary. Pins configured as outputs begin to function after RESET is released.
Table 5-21 is a summary of SCIM2 pin states during reset.
Pins that are not used should either be configured as outputs, or (if
configured as inputs) pulled to the appropriate inactive state. This
decreases additional I
supply level.
NOTES:
1. Module port pins may be in an indeterminate state for up to 15 milliseconds at
Module
MCCI
power-up.
1
Freescale Semiconductor, Inc.
For More Information On This Product,
Table 5-20 Module Pin Functions
Go to: www.freescale.com
Pin Mnemonic
RXDA/PMC6
RXDB/PMC4
TXDA/PMC7
TXDB/PMC5
MOSI/PMC1
MISO/PMC0
SCK/PMC2
SS/PMC3
DD
caused by digital inputs floating near mid-
NOTE
Discrete input
Discrete input
Discrete input
Discrete input
Discrete input
Discrete input
Discrete input
Discrete input
Function
MOTOROLA
5-51