PEB22554 SIEMENS [Siemens Semiconductor Group], PEB22554 Datasheet - Page 15

• Manufacturer Part Number: PEB22554
• Description: ICs for Communications
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Pin Definitions and Function (cont’d)
Pin No.
87
40
41
68
Semiconductor Group
Symbol
DBW
BHE/BLE
INT
IM
Input (I)
Output (O)
I
I
O/oD
I
Function
Bus High Enable (Siemens/Intel bus mode)
If 16-bit bus interface mode is enabled, this
signal indicates a data transfer on the upper
byte of the data bus (D8 … D15). In 8-bit bus
interface mode this signal has no function and
should be tied to
Bus Low Enable (Motorola bus mode)
If 16-bit bus interface mode is enabled, this
signal indicates a data transfer on the lower
byte of the data bus (D0 … D7). In 8-bit bus
interface mode this signal has no function and
should be tied to
Data Bus Width (Bus Interface Mode)
A low signal on this input selects the 8-bit bus
interface mode. A high signal on this input
selects the 16-bit bus interface mode. In this
case word transfer to/from the internal registers
is enabled. Byte transfers are implemented by
using A0 and BHE/BLE.
Interrupt Request
INT serves as general interrupt request which
may include all interrupt sources. These
interrupt sources can be masked via registers
IMR0 … 5. Interrupt status is reported via
registers GIS (Global Interrupt Status) and
ISR0 …5.
Output characteristics (push-pull active low/
high, open drain) are determined by
programming the IPC register.
Interface Mode
The level at this pin defines the bus interface
mode:
A low signal on this input selects the INTEL
interface mode. A high signal on this input
selects the Motorola interface mode.
15
V
V
DD
DD
.
.
Pin Descriptions E1
PEB 22554
09.98