![](http://datasheet.mmic.net.cn/290000/XPC801ZP25_datasheet_16187868/XPC801ZP25_43.png)
External Signals
2-6
MPC801
USER’S MANUAL
MOTOROLA
2
UPWAITA
GPLA4
A2
User Programmable Machine Wait A
to an external slave is controlled by the UPMA in the memory controller.
General-Purpose Line 4 on UPMA
—This output signal reflects the value specified in the UPMA in the
memory controller when an external transfer to a slave is controlled by the user programmable machine
A (UPMA).
—This input signal is sampled as you need it when an access
UPWAITB
GPLB4
A3
User Programmable Machine Wait B
to an external slave is controlled by the UPMB in the memory controller.
General-Purpose Line 4 on UPMB
—This output signal reflects the value specified in the UPMB in the
memory controller when an external transfer to a slave is controlled by the
machine
B (UPMB).
—This input signal is sampled as you need it when an access
user programmable
GPLA5
B3
General-Purpose Line 5 on UPMA
memory controller when an external transfer to a slave is controlled by the user programmable machine
A (UPMA). This signal can also be controlled by the UPMB.
—This output signal reflects the value specified in the UPMA in the
PORESET
M3
Power -On Reset
state.
—When asserted, this input signal causes the MPC801 to enter the power-on reset
RSTCONF
N2
Reset Configuration
HRESET signal. If it is asserted, the configuration mode is sampled in the form of the hard reset
configuration word driven on the data bus. When this signal is negated, the default configuration mode
is adopted by the MPC801. Notice that the initial base address of internal registers is determined in this
sequence.
—This input signal is sampled by the MPC801 during the assertion of the
HRESET
M2
Hard Reset
hard reset state.
—This open drain line, when asserted, causes the MPC801 external crystal to enter the
SRESET
L3
Soft Reset
reset state.
—This open drain line, when asserted, causes the MPC801 external crystal to enter the soft
XTAL
N1
This output signal is one of the connections to an external crystal for the internal oscillator circuitry.
EXTAL
M1
This signal is one of the connections to an external crystal for the internal oscillator circuitry.
XFC
O3
External Filter Capacitance
the PLL circuitry.
—This input signal is the connection pin to an external capacitor filter for
CLKOUT
P5
Clock Out
—This output signal is the clock system frequency.
EXTCLK
L1
External Clock
—This input signal is the external input clock from an external source.
TEXP
L2
Timer Expired
interface.
—This output signal reflects the status of the TEXPS bit in the PLPRCR in the CLOCK
DSCK/AT1
H4
Development Serial Clock
Address Type 1
transaction on the external bus. When the transaction is initiated by the internal core, it indicates if the
transfer is for problem or privilege state.
—This input signal is the clock for the debug port interface.
—This bidirectional three-state signal is driven by the MPC801 when it initiates a
IWP[0:1]
VFLS[0:1]
G1 and G2
Instruction Watchpoint 0-1
the program flow executed by the internal core.
Visible History Buffer Flushes Status
need program instructions flow tracking. They report the number of instructions flushed from the history
buffer in the internal core.
—These output signals report the detection of an instruction watchpoint in
—These output signals are output by the MPC801 when you
AT2
H2
Address Type 2
transaction on the external bus. When the transaction is initiated by the internal core, it indicates if the
transfer is instruction or data.
—This bidirectional three-state signal is driven by the MPC801 when it initiates a
Table 2-1. Signal Descriptions (Continued)
PIN NAME
PIN NUMBER
DESCRIPTION