Revision 1.31 – February 16, 2012
440EPx – PPC440EPx Embedded Processor
Data Sheet
Table 8. Signal Functional Description (Sheet 8 of 9)
Notes:
1. Receiver input has hysteresis
2. Must pull up (recommended value is 3kΩ to OV
(EOV
for Ethernet)
DD
DD
3. Must pull down (recommended value is 1kΩ)
4. If not used, must pull up (recommended value is 3kΩ to OV
(EOV
for Ethernet)
DD
DD
5. If not used, must pull down (recommended value is 1kΩ)
6. Strapping input during reset; pull-up or pull-down required
Signal Name
System Interface
Description
I/O
Type
Notes
3.3V tolerant
2.5V CMOS
SysClk
Main system clock input.
I
1
Set to 1 by an instruction machine check. The machine check is a
result of the attempted execution of an instruction transferred on
the PLB with a bus error. This output signal remains a logic 1
until the machine check error is cleared in the Exception
Syndrome Register (ESR).
3.3V tolerant
2.5V CMOS
SysErr
O
Main system reset. External logic can drive this bidirectional pin
low (minimum of 16 cycles) to initiate a system reset. A system
reset can also be initiated by software. Implemented as an open-
drain output (two states; 0 or open circuit).
3.3V tolerant
2.5V CMOS
SysReset
I/O
1, 2
3.3V LVTTL
Rcvr w/pull-up
Halt
Halt from external debugger.
I
I
TmrClk
Processor timer external input clock.
3.3V LVTTL
3.3V LVTTL
GPIO00:15
GPIO22:23
General purpose I/O. To access these functions, software must
set DCR register bits.
I/O
1
1
GPIO26:48
GPIO16:21
GPIO24:25
General purpose I/O. To access these functions, software must
set DCR register bits.
3.3V tolerant
2.5V CMOS
I/O
I/O
General purpose I/O. To access these functions, software must
set DCR register bits.
3.3V tolerant
2.5V CMOS
GPIO49:63
TestEn
3.3V LVTTL
Rcvr w/pull-
down
Test Enable.
I
I
I
Note: Do not connect for normal operation.
Receiver Inhibit. Active only when TestEn is active. Used for
manufacturing test only.
RcvrInh
3.3V LVTTL
1
1
3.3V tolerant
2.5V CMOS
Rcvr
Mode Control. Active only when TestEn is active. Used for
manufacturing test only.
ModeCtrl
LeakTest
LeakTest2
Leakage Test. Active only when TestEn is active. Used for
manufacturing test only.
3.3V LVTTL
w/pull-up
I
I
1
1
Reference Enable. Active only when TestEn is active. Used for
manufacturing test only.
RefEn
3.3V LVTTL
Driver Inhibit. Active only when TestEn is active. Used for
manufacturing test only.
3.3V LVTTL
w/pull-up
DrvrInh1:2
TherMonA:B
PSROOut
I
1
On-chip PNP thermal monitor transistor.
Thermal
monitor
I
5
A is the emitter and B is the base. The collector is grounded.
Module characterization and screening. Use for test purposes
only. Tie down as specified in Note 3 for normal operation.
Perf screen ring
oscillator
O
1, 3
64
AppliedMicro Proprietary
AMCC [ APPLIED MICRO CIRCUITS CORPORATION ]
