User`s manual

BL1600 System Development s 33
RX485
/CTS0
RXD1
TXD1
RXD0
TXD0
Z180
/CTS0
/RTS0
/RX0
/TX0
RS232CH1RX
RS232CH1TX
RXD0
TXD0
18 20
/RTS0
485
485+
TXD1
J1
to
H3
to
J2
25 23
24 26
J1
U4
(RS-232)
U9
(RS-485)
1
3
5
7
9
2
4
6
8
10
H4
/USER2 /DREQ0
/USER3 /DREQ1
/USER1
E
/RESET
/INT2
Figure 4-8. BL1600 Miscellaneous Signals
Header H4 Pinout
Figure 4-7 shows the configuration for one 5-wire RS-232 channel and one
2-wire RS-485 channel.
Figure 4-7. BL1600 Configuration for One 5-wire RS-232 Channel
and One 2-wire RS-485 Channel
The high-current output chip, U10, and the RS-485 driver, U9,
are coupled, so that disabling the RS-485 driver will also
disable the high-current output. The EN485 line may be used
as high-current output HC7 if RS-485 communication is not
needed.
Miscellaneous Signals
Header H4, shown in Figure4-8,
has three user lines, two DMA
request lines, and three miscel-
laneous signals. These signals
are provided to support cus-
tomer-designed expansion
boards for the BL1600. The sig-
nals are discussed briefly.
/USER1/USER3
Coupled with address lines A0A3, /USER1/USER3 allow you to read
and write to as many as 48 devices (registers) in your system. Only one
line asserts at any one time. Each line identifies a group of registers. The
groups have the following base addresses.
/USER1 0x150
/USER2 0x160
/USER3 0x170
A registers address is group + register#. For example, to read or write to
register 5 of group 2, use address 0x165.
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