Datasheet

DS2148/DS21Q48
10 of 73
2 PIN DESCRIPTION
The DS2148 can be controlled in a parallel port mode, a serial port mode, or a hardware mode (Table 2-1,
Table 2-2, and Table 2-3). The parallel and serial port modes are described in Section 3.2 and 3.3, and the
hardware mode is described below.
Table 2-1. Bus Interface Selection
BIS1 BIS0 PBTS BUS INTERFACE TYPE
0 0 0 Muxed Intel
0 0 1 Muxed Motorola
0 1 0 Nonmuxed Intel
0 1 1 Nonmuxed Motorola
1 0 - Serial Port
1 1 - Hardware
Table 2-2. Pin Assignment in Parallel Port Mode
DS2148T
PIN #
DS2148G
PIN#
I/O
PARALLEL
PORT MODE
1 C3 I
CS
2 C2 I
RD(DS)
3 B1 I
WR(R/W)
4 D2 I ALE(AS)
5 C1 I NA
6 D3 I NA
7 D1 I/O A4
8 E1 I A3
9 F2 I A2
10 F1 I A1
11 G1 I A0
12 E3 I/O D7/AD7
13 F3 I/O D6/AD6
14 G2 I/O D5/AD5
15 F4 I/O D4/AD4
16 G3 I/O D3/AD3
17 E4 I/O D2/AD2
18 G4 I/O D1/AD1
19 F5 I/O D0/AD0
20 G5 I VSM
21 F6 - V
DD
22 G6 - V
SS
23 E5 I/O
INT
24 E6 O PBEO
25 F7 O RCL/LOTC
26 D6 I TEST
27 D5 I RTIP
28 D7 I RRING