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Intel
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IXP42X product line and IXC1100 control plane processors—Expansion Bus Controller
Intel
®
IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
322 Order Number: 252480-006US
8.9.9 Configuration Register 0
At power up or whenever a reset is asserted, the expansion-bus address outputs are
switched to inputs and the states of the bits are captured and stored in Configuration
Register 0, bits 23 through 0. This occurs on the first cycle after the synchronous de-
assertion of the reset signal.
Table 123. Bit Level Definition for each of the Timing and Control Registers
Bits Name Description
31 CSx_EN
0 = Chip Select x disabled
1 = Chip Select x enabled
30 (Reserved)
29:28 T1 – Address timing
00 = Generate normal address phase timing
01 - 11 = Extend address phase by 1 - 3 clocks
27:26
T2 – Setup / Chip Select
Timing
00 = Generate normal setup phase timing
01 - 11 = Extend setup phase by 1 - 3 clocks
25:22 T3 – Strobe Timing
0000 = Generate normal strobe phase timing
0001-1111 = Extend strobe phase by 1 - 15 clocks
21:20 T4 – Hold Timing
00 = Generate normal hold phase timing
01 - 11 = Extend hold phase by 1 - 3 clocks
19:16 T5 – Recovery Timing
0000 = Generate normal recovery phase timing
0001-1111 = Extend recovery phase by 1 - 15 clocks
15:14 CYC_TYPE
00 = Configures the expansion bus for Intel cycles.
01 = Configures the expansion bus for Motorola* cycles.
10 = Configures the expansion bus for HPI cycles.
(HPI reserved for chip selects [7:4] only)
11 = Reserved
13:10 CNFG[3:0]
Device Configuration Size. Calculated using the formula:
SIZE OF ADDR SPACE = 2
(9+CNFG[3:0])
For Example:
0000 = Address space of 2
9
= 512 Bytes
…
1000 = Address space of 2
17
= 128 Kbytes
…
1111 = Address space of 2
24
= 16 Mbytes
9:7 (Reserved)
6BYTE_RD16
Byte read access to Half Word device
0 = Byte access disabled.
1 = Byte access enabled.
5HRDY_POL
HPI HRDY polarity (reserved for exp_cs_n[7:4] only)
0 = Polarity low true.
1 = Polarity high true.
4MUX_EN
0 = Separate address and data buses.
1 = Multiplexed address / data on data bus.
3SPLT_EN
0 = AHB split transfers disabled.
1 = AHB split transfers enabled.
2(Reserved)
1WR_EN
0 = Writes to CS region are disabled.
1 = Writes to CS region are enabled.
0BYTE_EN
0 = Expansion bus uses 16-bit-wide data bus.
1 = Expansion bus uses only 8-bit data bus.