
Smart Card Controller Programming Model
235
September 2005
SCPS110
13.13 Interrupt Line Register
The interrupt line register is programmed by the system and indicates to the software which interrupt line the
Smart Card interface has assigned to it. The default value of this register is FFh, indicating that an interrupt
line has not yet been assigned to the function.
Function 4 register offset: 3Ch
Register type:
Read/Write
Default value:
FFh
BIT NUMBER
7
6
5
4
3
2
1
0
RESET STATE
1
13.14 Interrupt Pin Register
This register decodes the interrupt select inputs and returns the proper interrupt value based on Table 137,
indicating that the Smart Card interface uses an interrupt. If one of the USE_INTx terminals is asserted, the
interrupt select bits are ignored, and this register returns the interrupt value for the highest priority USE_INTx
terminal that is asserted. If bit 28, the tie-all bit (TIEALL), in the system control register (PCI offset 80h, see
Section 4.29) is set to 1b, then the controller asserts the USE_INTA input to the Smart Card controller core.
If bit 28 (TIEALL) in the system control register (PCI offset 80h, see Section 4.29) is set to 0b, then none of
the USE_INTx inputs are asserted and the interrupt for the Smart Card function is selected by the INT_SEL
bits in the Smart Card general control register.
Function 4 register offset: 3Dh
Register type:
Read-only
Default value:
0Xh
BIT NUMBER
7
6
5
4
3
2
1
0
RESET STATE
0
X
Table 137. PCI Interrupt Pin Register
INT_SEL BITS
USE_INTA
INTPIN
00
0
01h (INTA)
01
0
02h (INTB)
10
0
03h (INTC)
11
0
04h (INTD)
XX
1
01h (INTA)
13.15 Minimum Grant Register
The minimum grant register contains the minimum grant value for the Smart Card controller core.
Function 4 register offset: 3Eh
Register type:
Read/Update
Default value:
00h
BIT NUMBER
7
6
5
4
3
2
1
0
RESET STATE
0
Table 138. Minimum Grant Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
70
MIN_GNT
RU
Minimum grant. The contents of this field may be used by host BIOS to assign a latency timer register value
to the Smart Card controller. The default for this register indicates that the Smart Card controller may need
to sustain burst transfers for nearly 64
s and thus request a large value be programmed in bits 158 of
the latency timer and class cache line size register at offset 0Ch in the PCI configuration space (see
Section 13.6).