PEB22554 SIEMENS [Siemens Semiconductor Group], PEB22554 Datasheet - Page 191

• 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
V
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
V
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.
DD
DD
. Refer to chapter 7.2 for detailed information.
. Refer to chapter 7.2 for detailed information.
191
General Features T1
PEB 22554
09.98