Intel IXC1100, IXP42X Table 146. GPIO Clock Frequency Select, Table 147. GPIO Duty Cycle Select (Sheet 1 of 2)

Intel® IXP42X product line and IXC1100 control plane processors—General Purpose Input/
Output (GPIO)
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
390 Order Number: 252480-006US
Table 146. GPIO Clock Frequency Select
Frequency GPIO15 – Frequency Terminal Count GPIO14 – Frequency Terminal Count
Bit 23 Bit 22 Bit 21 Bit 20 Bit 7 Bit 6 Bit 5 Bit 4
logic 1 0 0 0 0 0 0 0 0
33.33 MHz 0 0 0 1 0 0 0 1
22 MHz 0 0 1 0 0 0 1 0
16.5 MHz 0 0 1 1 0 0 1 1
13.2 MHz 0 1 0 0 0 1 0 0
11 MHz 0 1 0 1 0 1 0 1
9.43 MHz 0 1 1 0 0 1 1 0
8.25 MHz 0 1 1 1 0 1 1 1
7.33 MHz 1 0 0 0 1 0 0 0
6.6 MHz 1 0 0 1 1 0 0 1
6 MHz 1 0 1 0 1 0 1 0
5.5 MHz 1 0 1 1 1 0 1 1
5.08 MHz 1 1 0 0 1 1 0 0
4.71 MHz 1 1 0 1 1 1 0 1
4.4 MHz 1 1 1 0 1 1 1 0
4.125 MHz†11111111
† When the value of the GPIO frequency terminal count is set to 0xF and the value of the GPIO duty
cycle terminal count is set to 0xF, the associated GPIO (GPIO14 or GPIO 15) will output a clock of
33.33 MHz with a 50% duty cycle.
Table 147. GPIO Duty Cycle Select (Sheet 1 of 2)
Duty Cycle
(Low Time)
GPIO15 – Duty Cycle Terminal Count GPIO14 – Duty Cycle Terminal Count
Bit 19 Bit 18 Bit 17 Bit 16 Bit 3 Bit 2 Bit 1 Bit 0
15 ns 0 0 0 0 0 0 0 0
30 ns 0 0 0 1 0 0 0 1
45 ns 0 0 1 0 0 0 1 0
60 ns 0 0 1 1 0 0 1 1
75 ns 0 1 0 0 0 1 0 0
90 ns 0 1 0 1 0 1 0 1
105 ns 0 1 1 0 0 1 1 0
120 ns 0 1 1 1 0 1 1 1
135 ns 1 0 0 0 1 0 0 0
150 ns 1 0 0 1 1 0 0 1
165 ns 1 0 1 0 1 0 1 0
180 ns 1 0 1 1 1 0 1 1
190 ns 1 1 0 0 1 1 0 0