Revision 2.03 – September 7, 2007
405GP – Power PC 405GP Embedded Processor
Data Sheet
Strapping
When the SysReset input is driven low by an external device (system reset), the state of certain I/O pins is read to
enable default initial conditions prior to PPC405GP start-up. The actual capture instant is the nearest SysClk edge
before the deassertion of reset. These pins must be strapped using external pull-up (logical 1) or pull-down
(logical 0) resistors to select the desired default conditions. The recommended pull-up is 3kΩ to +3.3V or 10kΩ to
+5V. The recommended pull-down is 1KΩ to GND. These pins are use for strap functions only during reset. They
are used for other signals during normal operation. The following table lists the strapping pins along with their
functions and strapping options. The pin for the 456-ball package is listed first (for example, AF3), followed by the
corresponding pin for the 413-ball package (for example, U8), which appears as AF3/U8. The signal names
assigned to the pins for normal operation follow the pin numbers.
PPC405GP Strapping Pin Assignments (Part 1 of 2)
Function
Option
Ball Strapping
PLL Tuning 1
AF3/U8
AF2/T8
AD16/AB15
UART0_Tx
UART0_DTR
UART0_RTS
for 6 ≤ M ≤ 7 use choice 3
for 7 < M ≤ 12 use choice 5
for 12 < M ≤ 32 use choice 6
Choice 1; TUNE[5:0] = 010001
Choice 2; TUNE[5:0] = 111011
Choice 3; TUNE[5:0] = 010011
Choice 4; TUNE[5:0] = 111101
Choice 5; TUNE[5:0] = 010101
Choice 6; TUNE[5:0] = 010110
Choice 7; TUNE[5:0] = 111110
Choice 8; TUNE[5:0] = 100100
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
PLL Forward Divider 2
PLL Feedback Divider 2
PLB Divider from CPU 2
OPB Divider from PLB 2
D16/A17
B15/B14
DMAAck0
DMAAck1
Bypass mode
Divide by 3
Divide by 4
Divide by 6
0
0
1
1
0
1
0
1
B14/A15
DMAAck2
C12/A8
DMAAck3
Divide by 1
Divide by 2
Divide by 3
Divide by 4
0
0
1
1
0
1
0
1
P25/R23
EMCTxD3
L24/J22
EMCTxD2
Divide by 1
Divide by 2
Divide by 3
Divide by 4
0
0
1
1
0
1
0
1
L25/K21
EMCTxD1
J26/F22
EMCTxD0
Divide by 1
Divide by 2
Divide by 3
Divide by 4
0
0
1
1
0
1
0
1
AMCC
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