SC2200 NSC [National Semiconductor], SC2200 Datasheet - Page 87

• Manufacturer Part Number: SC2200
• Description: Thin Client On a Chip
• Manufacturer: NSC [National Semiconductor]

Revision 3.0
General Configuration Block
Offset 38h
This register selects the IRQ signal of the combined WATCHDOG and High-Resolution timer interrupt. This interrupt is shareable with
other interrupt sources.
Offset 39h-3Bh
Offset 3Ch
This register identifies the IA On a Chip device. SC2200 = 04h.
Offset 3Dh
This register identifies the device revision. See device errata for value.
Offset 3Eh-3Fh
This register sets the base address of the Configuration block.
15:6
7:4
3:0
5:0
Bit
0
Table 3-2. Multiplexing, Interrupt Selection, and Base Address Registers (Continued)
Description
SDBE0 (Slave Disconnect Boundary Enable). Works in conjunction with the GX1 module’s PCI Control Function 2 Regis-
ter (Index 41h), bit 1 (SDBE1). Sets boundaries for when the GX1 module is a PCI slave.
SDBE[1:0]
00: Read and Write disconnect on boundaries set by bits [3:2] of the GX1 module’s PCI Control Function 2 register (Index
01: Write disconnects on boundaries set by bits [3:2] of the GX1 module’s PCI Control Function 2 register. Read discon-
1x: Read and Write disconnect on cache line boundary of 16 bytes.
This bit is reset to 1.
All PCI bus masters (including SC2200’s on-chip PCI bus masters, e.g., the USB Controller) must be disabled while modify-
ing this bit. When accessing this register while any PCI bus master is enabled, use read-modify-write to ensure these bit
contents are unchanged.
Reserved. Write as read.
CBIRQ. Configuration Block Interrupt.
0000: Disable
0001: IRQ1
0010: Reserved
0011: IRQ3
Configuration Base Address. These bits are the high bits of the Configuration Base Address.
Configuration Base Address. These bits are the low bits of the Configuration Base Address. These bits are set to 0.
41h).
nects on cache line boundary of 16 bytes.
IA On a Chip Identification Number Register - IID (RO)
Configuration Base Address Register - CBA (RO)
0100: IRQ4
0101: IRQ5
0110: IRQ6
0111: IRQ7
Interrupt Selection Register - INTSEL (R/W)
(Continued)
Revision Register - REV (RO)
Reserved - RSVD
87
1000: IRQ8#
1001: IRQ9
1010: IRQ10
1011: IRQ11
1100: IRQ12
1101: Reserved
1110: IRQ14
1111: IRQ15
Reset Value: 00h
Reset Value: xxh
Reset Value: xxh
Reset Value: xxh
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