Revision 1.15 – August 30, 2007
440GX – Power PC 440GX Embedded Processor
Data Sheet
Signal Functional Description (Sheet 5 of 8)
Notes:
1. Receiver input has hysteresis
2. Must pull up (recommended value is 3kΩ to 3.3V)
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
Description
I/O
Type
Notes
Used by either peripheral controller or DMA controller depending
upon the type of transfer involved. When the PPC440GX is the
bus master, it enables the selected device to drive the bus.
PerOE
O
3.3V LVTTL
2
1
PerPar0:3
PerReady
External peripheral data bus byte parity.
I/O
I
3.3V LVTTL
3.3V LVTTL
Used by a peripheral slave to indicate it is ready to transfer data.
Used by the PPC440GX when not in external master mode, as
output by either the peripheral controller or DMA controller
depending upon the type of transfer involved. High indicates a
read from memory, low indicates a write to memory.
PerR/W
PerWE
I/O
O
3.3V LVTTL
3.3V LVTTL
1, 2
2
Otherwise, it used by the external master as an input to indicate
the direction of transfer.
Write Enable. Low when any of the four PerWBE0:3 signals are
low.
External Master Peripheral Interface
Bus Request. Used when the PPC440GX needs to regain control
of peripheral interface from an external master.
BusReq
ExtAck
O
O
I
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
External Acknowledgement. Used by the PPC440GX to indicate
that a data transfer occurred.
External Request. Used by an external master to indicate it is
prepared to transfer data.
ExtReq
ExtReset
HoldAck
HoldReq
PerClk
1, 4
Peripheral Reset. Used by an external master and by
synchronous peripheral slaves.
O
O
I
Hold Acknowledge. Used by the PPC440GX to transfer ownership
of peripheral bus to an external master.
Hold Request. Used by an external master to request ownership
of the peripheral bus.
1, 5
1, 5
1, 4
Peripheral Clock. Used by an external master and by synchronous
peripheral slaves.
O
I/O
External Error. Used as an input to record external master errors
and external slave peripheral errors.
PerErr
UART Peripheral Interface
Serial clock input that provides an alternative to the internally
generated serial clock. Used in cases where the allowable
internally generated clock rates are not satisfactory. This input can
be individually connected to either or both UART0 and UART1.
UARTSerClk
I
3.3V LVTTL
UART0_Rx
UART0_Tx
UART0 Receive data.
I
O
I
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
3.3V LVTTL
1, 4
4
UART0 Transmit data.
UART0_DCD
UART0_DSR
UART0_CTS
UART0_DTR
UART0_RTS
UART0_RI
UART0 Data Carrier Detect.
UART0 Data Set Ready.
UART0 Clear To Send.
UART0 Data Terminal Ready.
UART0 Request To Send.
UART0 Ring Indicator.
6
I
6
I
1, 4
4
O
O
I
4
1, 4
54
AMCC
AMCC [ APPLIED MICRO CIRCUITS CORPORATION ]
