Revision 1.07 – October 4, 2007
440GP – Power PC 440GP Embedded Processor
Data Sheet
Signal Functional Description (Sheet 6 of 7)
Notes:
1. Receiver input has hysteresis
2. Must pull up (recommended value is 3kΩ to 3.3V, 10kΩ to 5V)
3. Must pull down (recommended value is 1kΩ)
4. If not used, must pull up (recommended value is 3kΩ to 3.3V)
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
5V tolerant
SysClk
SysErr
Main system clock input.
Clock
O
3.3V LVTTL
5V tolerant
3.3V LVTTL
Set to 1 when a machine check is generated.
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. The signal is implemented
as an open-drain output (two states; 0 or open circuit).
During chip power-up, this signal must be low from the start of VDD
ramp-up until at least 16 SysClk cycles after VDD is stable.
5V tolerant
3.3V LVTTL
SysReset
I/O
1, 2
5V tolerant
TmrClk
Halt
Processor timer external input clock.
Halt from external debugger.
I
3.3V LVTTL
5V tolerant
3.3V LVTTL
I
1, 4
General purpose I/O 0 through 10. To access these functions,
software must set DCR register bits.
5V tolerant
GPIO00:31
TestEn
I/O
3.3V LVTTL
1.8V CMOS
w/pull-down
Test Enable.
I
I
I
I
3
5V tolerant
3.3V LVTTL
RcvrInh
RefVEn
DrvrInh1:2
Receiver Inhibit. Active only when TestEn is active.
Reference Voltage Enable. Do not connect for normal operation.
Pull up for Boundary Scan Description Language (BSDL) testing.
1.8V CMOS
w/pull-down
Driver Inhibit. Used for test purposes only. Tie up for normal
operation
5V tolerant
3.3V LVTTL
2
AMCC
53