
3.0 Device Architecture and Configuration
(Continued)
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3.15 X-BUS CONFIGURATION
This section is relevant only for the PC87416 and PC87417.
3.15.1
Table 27 lists the configuration registers that affect the X-Bus functional block. The X-Bus base address registers point to
the X-Bus runtime registers described in Section 5.4 on page 107. The memory space to which the X-Bus responds is de-
fined by the configuration registers described in the sections below. See Section 3.2.3 on page 40 for a detailed description
of the other configuration registers. The standard configuration registers are powered by V
DD
, however the specific config-
uration registers are powered by V
SB
.
Logical Device F (X-Bus) Configuration
Table 27. X-Bus Configuration Registers
3.15.2
LPC I/O transactions can be forwarded to the X-Bus of the PC8741x device. The X-Bus I/O configuration registers define
the map of I/O addresses to be forwarded. The PC8741x provides five individually enabled I/O zones. Each zone generates
an internal select signal that is sent to the X-Bus functional block. The mapping of the internal select signals to the XCS0-3
signals of the PC8741x device is controlled by the X-Bus functional block. See Section 5.2 on page 92 for further details.
The supported I/O zones are:
X-Bus I/O Range Programming
G
User-Defined I/O Zone 0 through 3 (UDIZ0-3) - specified using the zone size (2
n
where n is 0 through 8) and start
address (must be aligned with the zone size).
G
Debug Port Address (TST) - This zone is for debug use only.
Index
Configuration Register or Action
Type
Power Well
Reset
30h
Activate (see Section 3.3.1 on page 43). When bit 0 is cleared, the
registers of this logical device are not accessible.
R/W
V
DD
00h
60h
Base Address MSB register.
R/W
V
DD
00h
61h
Base Address LSB register. Bits 4-0 (for A4-A0) are read only, 00000b. Varies per bit
V
DD
00h
70h
Interrupt Number and wake-up on IRQ enable.
RO
V
DD
00h
71h
Interrupt Type.
RO
V
DD
00h
74h
Report no DMA assignment.
RO
V
DD
04h
75h
Report no DMA assignment.
RO
V
DD
04h
F0h
X-Bus I/O Configuration register (XIOCNF).
Varies per bit
V
SB
00h
F1h
X-Bus I/O Base Address 1 High Byte register (XIOBA1H).
R/W or RO
V
SB
00h
F2h
X-Bus I/O Base Address 1 Low Byte register (XIOBA1L).
R/W or RO
V
SB
00h
F3h
X-Bus I/O Size 1 Configuration register (XIOSIZE1).
R/W or RO
V
SB
00h
F4h
X-Bus I/O Base Address 2 High Byte register (XIOBA2H).
R/W or RO
V
SB
00h
F5h
X-Bus I/O Base Address 2 Low Byte register (XIOBA2L).
R/W or RO
V
SB
00h
F6h
X-Bus I/O Size 2 Configuration register (XIOSIZE2).
R/W or RO
V
SB
00h
F7h
X-Bus Memory Configuration register 1 (XMEMCNF1).
R/W or RO
V
SB
00h
F8h
X-Bus Memory Configuration register 2 (XMEMCNF2).
Varies per bit
V
SB
00h
F9h
X-Bus Memory Base Address High Byte register (XMEMBAH).
R/W or RO
V
SB
00h
FAh
X-Bus Memory Base Address Low Byte register (XMEMBAL).
R/W or RO
V
SB
00h
FBh
X-Bus Memory Size Configuration register (XMEMSIZE).
R/W or RO
V
SB
00h
FCh
X-Bus IRQ Mapping register (XIRQMAP).
R/W
V
SB
00h