XC68HC705JJ7 Motorola, XC68HC705JJ7 Datasheet - Page 98

• Manufacturer Part Number: XC68HC705JJ7
• Description: MICROCONTROLLER
• Manufacturer: Motorola

Parallel Input/Output
7.4.8 PB6/SDI Logic
Advance Information
98
WRITE $0005
WRITE $0001
WRITE $0011
RESET
READ $0005
READ $0001
The PB6/SDI pin can be used as a simple I/O port pin or be controlled
by the SIOP serial interface as shown in
PB6/SDI pin are summarized in
When using the PB6/SDI pin, these interactions must be noted:
SERIAL DATA IN (SDI)
1. If the SIOP function is required, then the SPE bit in the SCR must
2. If the SIOP function is in control of the PB6/SDI pin, the DDRB6
SERIAL ENABLE (SPE)
R
R
Figure 7-11. PB6/SDI Pin I/O Circuit
PORT B DATA
be set. This causes the PB6/SDI pin buffer to be disabled to allow
the PB6/SDI pin to act as an input that feeds the serial data input
(SDI) of the SIOP. The pulldown device is disabled in this case.
and PB6 data register bits are still accessible to the CPU and can
be altered or read without affecting the SIOP functionality.
However, if the DDRB6 bit is cleared, reading the PB6 data
register will return the current state of the PB6/SDI pin.
REGISTER
DATA DIRECTION
BIT PB6
REGISTER B
REGISTER B
PULLDOWN
BIT DDRB6
BIT PDIB6
Parallel Input/Output
MASK OPTION REG. ($1FF1)
Table
MC68HC705JJ7 • MC68HC705JP7 — REV 4
7-3.
Figure
7-11. The operations of
PULLDOWN
DEVICE
PB6
SDI
MOTOROLA