SAB 82525
SAB 82526
SAF 82525
SAF 82526
Specific Applications
HSCX with SAB 8051 Microcontroller
For cost-sensitive applications, the HSCX can be interfaced with a small SAB 8051
microcontroller system (without DMA support) very easily as shown in figure 3.
+5 V
+5 V
DACKA
INT
DACKB
INT0
RD
RD
RD
Channel A
Channel B
WR
ALE
WR
ALE
WR
ALE
CS
SAB 8051
CPU
SAB 82525
HSCX
A8 - A15
A0 - A6
D0 - D7
AD0 - AD7
Latch
AD0 - AD7
IM1
Common Bus
A0 - A15,D0 - D7
Memory
ITS00948
Figure 3
HSCX with 8051 CPU
Although the HSCX provides a demultiplexed bus interface, it can optionally be connected
directly to the local multiplexed bus of SAB 8051 because of the internal address latch function
(via ALE, compatibility to SAB 82520 HSCC).
The address lines A0 … A6 must be wired externally to the data lines D0 … D6 (direct
connection) in this case.
Intel bus mode is selected connecting IM1 pin to low (VSS). Since data transfer is controlled by
interrupt, the DMA acknowledge inputs (DACKA, DACKB) are connected to VDD (+ 5 V).
Semiconductor Group
18
SIEMENS [ Siemens Semiconductor Group ]
