BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
376
Section 11: Generic/Boot Bus
Document
1250_1125-UM100CB-R
Table 255: Generic Bus Region Timing 1 Registers
io_ext_time_cfg1_0 -
00_1006_1700 (defaults for boot ROM)
io_ext_time_cfg1_1 -
00_1006_1708
io_ext_time_cfg1_2 -
00_1006_1710
io_ext_time_cfg1_3 -
00_1006_1718
io_ext_time_cfg1_4 -
00_1006_1720
io_ext_time_cfg1_5 -
00_1006_1728
io_ext_time_cfg1_6 -
00_1006_1730
io_ext_time_cfg1_7 -
00_1006_1738
A write to any bit causes all bits to be written.
Bits
Name
Default
Description
2:0
io_ale_to_write
_0
3’h7
3'h1
Assertion of write strobe after the deassertion of ALE.
3
rdy_sync
1'b0
If this bit is clear the IO_RDY input is an asynchronous input and will be internally
synchronized so there is no need for the peripheral to meet the setup and hold
specification on the signal. If this bit is set the synchronizer is bypassed, so the
acknowledgement is detected earlier by the generic bus state machine, but the
peripheral must meet the setup and hold time specification.
7:4
io_write_width
_0
4’h7
4'h1
Width of the write strobe
11:8
io_idle_cycle
_0
4’h6
4'h1
Number of idle cycles between back_to_back operations.
13:12
io_oe_to_cs
2'h0
Number of cycles IO_OE_L deasserts before IO_CS_L deasserts. In
acknowledgement mode this parameter is also the number of cycles between
IO_WR_L deasserts and IO_CS_L deasserts.
15:14
io_cs_to_oe
2'h0
Number of cycles between IO_CS_L assertion and IO_OE_L assertion. This
parameter must be less than io_cs_width.
63:16
notimp
48’bx
Not implemented.
Table 256: Generic Bus Interrupt Status Register
io_interrupt_status -
00_1006_1A00
READ ONLY (Read clears interrupt)
Bits
Name
Default
Description
7:0
io_cs_err_int
8'h0
Indicates which of the 8 chip select regions have an error resulting in an interrupt. This
field is only valid when one or more of bits [9], [10], [13], or [14] are set.
8
reserved
1'b0
Not used, reads as zero.
9
io_rd_par_int
1'b0
When high, indicates parity error on read data from a parity enabled device. The
address of the 32 bit word accessed will be put in the address log, the data in the
appropriate part of the data log, and the parity in the appropriate part of the parity log.
10
io_timeout_int
1'b0
When high, indicates timeout has occurred on one of the IO blocks. The address that
was being accessed is put in the address log.
11
io_ill_addr_int
1'b0
When high, indicates an address referenced did not match any region. The address
that was being accessed is put in the address log.
12
io_mult_cs_int
1'b0
When high, indicates multiple chip selects selected based on the address accessed.
The address that was being accessed is put in the address log.