71
Tsi308 User Manual
80D4000_MA001_02
Tundra Semiconductor Corporation
www.tundra.com
®
3.
Clock Frequency and Mode Selection
Hardware Straps
This chapter discusses the following topics about the Tsi308:
•
•
“Core Clock Frequency Selection in RevC mode” on page 73
•
“PCI Bus A Frequency Selection in RevC mode” on page 74
•
“PCI Bus B Frequency Selection in RevC mode” on page 74
•
“PCI Bus A and Core Clock Frequency Selection in non-RevC mode” on page 75
•
“PCI Bus B Frequency Selection in non-RevC mode” on page 76
•
“Link Frequency Selection (Tsi301 mode only)” on page 76
•
“Miscellaneous Straps” on page 78
3.1
Overview
Tsi308 has five PLLs: HT0_PLL_0, HT1_PLL_1, CORE_PLL, PCI_A_PLL and PCI_B_PLL.
The reference clock for the first three PLLs is REFCLK_C in RevC mode and P0_CLK in
non-RevC mode. The reference clock for PCI_A_PLL is P0_CLK and the reference clock for
PCI_B_PLL is P1_CLK.
•
HT0_PLL generates the HyperTransport transmit clock for Link 0.
•
HT1_PLL generates the HyperTransport transmit clock for Link 1.
•
CORE_PLL generates the clock for core logic.
•
PCI_A_PLL generates the clock (PCI_CLK_A ) for PCI bus A interface logic.
•
PCI_B_PLL generates the clock(PCI_CLK_B) for PCI bus B interface logic.
Tsi308 Revision C is backward pin compatible with previous revisions(A & B). Tsi308 Revision
C device can be dropped into the boards made for previous revisions. AD[15] is used to select
between RevC or non-RevC modes. AD[15] = 1 for RevC mode and AD[15] = 0 for non-RevC
mode.
Summary of Contents for TSI308
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