Motorola MCF5281 사용자 설명서
MOTOROLA
Chapter 14. Signal Descriptions
14-17
Overview
listing of signals that do not default to a GPIO function.
14.1.2 External Boot Mode
When booting from external memory, the address bus, data bus, and bus control signals will
default to their bus functionalities as shown in Table 14-5. As in single-chip mode, the
signals listed in Table 14-4 will operate as described above. All other signals will default to
GPIO inputs.
default to their bus functionalities as shown in Table 14-5. As in single-chip mode, the
signals listed in Table 14-4 will operate as described above. All other signals will default to
GPIO inputs.
Table 14-4. Pin Reset States at Reset (Single-Chip Mode)
Signal
Reset
I/O
Clock and Reset Signals
RSTI
—
I
RSTO
Low
O
EXTAL
—
I
XTAL
XTAL
O
CLKOUT
CLKOUT
O
Debug Support Signals
JTAG_EN
—
I
DSCLK/TRST
—
I
BKPT/TMS
—
I
DSI/TDI
—
I
DSO/TDO
High
O
TCLK
—
I
DDATA[3:0]
DDATA{3:0]
O
PST[3:0]
PST[3:0]
O
Table 14-5. Default Signal Functions After System
Reset (External Boot Mode)
Signal
Reset
I/O
A[23:0]
A[23:0]
O
D[31:0]
—
I/O
BS[3:0]
High
O
OE
High
O
TA
—
I
TEA
—
I
R/W
High
O
SIZ[1:0]
High
O