CH Tech i4000 user manual Address Mapping, Example

i4000 - Quad M-module carrier for VMEbus
User Manual	Version: 1.2

5.1.2.ADDRESS MAPPING

As mentioned before the address space occupied by the i4000 board is 0x800 bytes (A0-A10). These 0x800 bytes are divided into 4 identical spaces. Every 0x200 bytes block is assigned to a module slot. The first 0x100 bytes address space are assigned to the module itself and the second 0x100 bytes are used for the access part of the interrupt controller.

Using this method of address decoding provides an identical address map of each module on the i4000 board. This makes writing the software easier since just the base address of the module, not the base address of the i4000 has to be known. Every module has its own Interrupt-Vector and Interrupt-Control register. The 0x100 bytes from each module used to access the interrupt controller are not completely decoded. Both registers of the interrupt controller are mirrored several times within the 0x100 bytes address space. Decoding of the M-module’s 0x100 bytes of address space is done on the used M-module.

Address map of the i4000

0x000..0x0ff	Module
0x101	Control register (CR0)	Module 0
0x103	Vector register (VR0
0x200..0x2ff	Module
0x301	Control register (CR1)	Module 1
0x303	Vector register (VR1)
0x400..0x4ff	Module
0x501	Control register (CR2)	Module 2
0x503	Vector register (VR2)
0x600..0x6ff	Module
0x701	Control register (CR3)	Module 3
0x703	Vector register (VR3)

The base address of a module can be calculated using the following formula:

ModuleBaseAddress = i4000BaseAddress + ModuleNumber * 0x200

EXAMPLE:

The installed base address of the i4000 is 0x800000. A module is fitted into slot 2. The module base address is then 0x800000 + 2 * 0x200 = 0x800400. When using a 32 bit master, which accesses the standard address space at address 0xff??????, the module will be accessed at address 0xff800400. The corresponding interrupt control register address is then 0xff800501.

	AcQuisition Technology bv
	P.O. Box 627, 5340 AP
Page 20 of 25	Oss, The Netherlands