Motorola ColdFire MCF5281 - Manual (Page 258)

Signal Descriptions
14-18 Freescale Semiconductor
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.
14.2 External Signals
The following sections describe the external signals on the device.
14.2.1 External Interface Module (EIM) Signals
These signals are used for doing transactions on the external bus.
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
TS High O
TIP High O
CS[6:0] High O
Table 14-4. Pin Reset States at Reset (Single-Chip Mode) (continued)
Signal Reset I/O
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3