SH7751 Group, SH7751R Group
Section 22 PCI Controller (PCIC)
R01UH0457EJ0301 Rev. 3.01
Page 917 of 1128
Sep 24, 2013
22.2.34
I/O Space Base Register (PCIIOBR)
Bit:
31 30 29 28 27 26 25 24
IOBR31 IOBR30 IOBR29
IOBR28
IOBR27
IOBR26
IOBR25 IOBR24
Initial
value:
0 0 0 0 0 0 0 0
PCI-R/W:
— — — — — — — —
PP
Bus-R/W:
R/W R/W R/W R/W R/W R/W R/W R/W
Bit:
23 22 21 20 19 18 17 16
IOBR23 IOBR22 IOBR21
IOBR20
IOBR19
IOBR18
—
—
Initial
value:
0 0 0 0 0 0 0 0
PCI-R/W:
— — — — — — — —
PP
Bus-R/W:
R/W R/W R/W R/W R/W R/W R
R
Bit:
15 14 13 12 11 10 9 8
— — — — — — — —
Initial
value:
0 0 0 0 0 0 0 0
PCI-R/W:
— — — — — — — —
PP
Bus-R/W:
R R R R R R R R
Bit:
7 6 5 4 3 2 1 0
— — — — — — —
LOCK
Initial
value:
0 0 0 0 0 0 0 0
PCI-R/W:
— — — — — — — —
PP
Bus-R/W:
R R R R R R R
R/W
The I/O space base register (PCIIOBR) species the most significant 14 bits of the address of the
PCI I/O space when performing I/O read and I/O write operations by PIO transfer. It also specifies
locked transfers. This 32-bit read/write register can be accessed from the PP bus.
All bits of the PCII0BR register are initialized to 0 at a power-on reset. They are not initialized at
a software reset.
Setting bit 0 (LOCK) to 1 locks the I/O space for PIO transfers while the bit remains set. A locked
transfer consists of the combined read and write operations. Do not attempt to perform other PIO
transfers during the locked combination of read and write operations.