Texas Instruments PCI7421 manual ExCA Address Window Enable Register, ExCA address window enable

5.7 ExCA Address Window Enable Register

The ExCA address window enable register enables/disables the memory and I/O windows to the 16-bit PC Card. By default, all windows to the card are disabled. The PCI7x21/PCI7x11 controller does not acknowledge PCI memory or I/O cycles to the card if the corresponding enable bit in this register is 0, regardless of the programming of the memory or I/O window start/end/offset address registers. See Table 5−9 for a complete description of the register contents.

Bit	7	6	5	4	3	2	1	0
Name				ExCA address window enable
Type	RW	RW	R	RW	RW	RW	RW	RW
Default	0	0	0	0	0	0	0	0

Register:	ExCA address window enable
Type:	Read-only, Read/Write
Offset:	CardBus socket address + 806h;

Card A ExCA offset 06h Card B ExCA offset 46h

	Default:	00h
		Table 5−9. ExCA Address Window Enable Register Description
BIT	SIGNAL	TYPE		FUNCTION
			I/O window 1 enable. Bit 7 enables/disables I/O window 1 for the PC Card. This bit is encoded as:
7	IOWIN1EN	RW	0 = I/O window 1 disabled (default)
			1	= I/O window 1 enabled
			I/O window 0 enable. Bit 6 enables/disables I/O window 0 for the PC Card. This bit is encoded as:
6	IOWIN0EN	RW	0 = I/O window 0 disabled (default)
			1	= I/O window 0 enabled
5	RSVD	R	Reserved. Bit 5 returns 0 when read.
			Memory window 4 enable. Bit 4 enables/disables memory window 4 for the PC Card. This bit is
4	MEMWIN4EN	RW	encoded as:
			0	= Memory window 4 disabled (default)
			1	= Memory window 4 enabled
			Memory window 3 enable. Bit 3 enables/disables memory window 3 for the PC Card. This bit is
3	MEMWIN3EN	RW	encoded as:
			0	= Memory window 3 disabled (default)
			1	= Memory window 3 enabled
			Memory window 2 enable. Bit 2 enables/disables memory window 2 for the PC Card. This bit is
2	MEMWIN2EN	RW	encoded as:
			0	= Memory window 2 disabled (default)
			1	= Memory window 2 enabled
			Memory window 1 enable. Bit 1 enables/disables memory window 1 for the PC Card. This bit is
1	MEMWIN1EN	RW	encoded as:
			0	= Memory window 1 disabled (default)
			1	= Memory window 1 enabled
			Memory window 0 enable. Bit 0 enables/disables memory window 0 for the PC Card. This bit is
0	MEMWIN0EN	RW	encoded as:
			0	= Memory window 0 disabled (default)
			1	= Memory window 0 enabled

5−11