CD2231 Intel Corporation, CD2231 Datasheet - Page 65

• Manufacturer Part Number: CD2231
• Description: CD2231 Intelligent Two-channel Lan And Wan Communications Controller
• Manufacturer: Intel Corporation

5.6.1
5.6.2
5.6.3
Datasheet
†. Reference: CCITT 1988 Blue Book.
Figure 14. DMA Connections for the CD2231
Interface to a 32-Bit Data Bus
To interface to a 32-bit data bus, two 16-bit data buffers must be used to isolate the CD2231 A/
D[0–15] pins from either half of the 32-bit bus. The A[1] address pin determines if the lower or
upper half of the data bus is in use for a particular bus cycle. The CD2231 always drives all 16 data
bits during a register-read or DMA-write operation, regardless of the size of the actual transfer.
DMA Connections for the CD2231
NOTES:
CD2231 as a DTE and DCE Interface
Table 10
CD2231 and RS-232C standard interfaces.
1. The 24-bit latch is required.
2. The 16-bit Xcvr is optional depending on application.
3. The 32-bit driver is optional depending on drive needs.
Intelligent Two-Channel LAN and WAN Communications Controller — CD2231
shows the recommended DTE (data terminal equipment) connections between the
DATEN*
DATDIR*
R/W*
DS*
DTACK*
A/D [0–15]
ADLD*
A[0–7]
AEN*
AS*
en
dir
[16–31]
STROBE*
[8–15]
LATCH
24-BIT
16-BIT
DATA
Xcvr
[8–31]
DATA[0–15]
[0–7]
†
ADDRESS
DRIVER
32-BIT
MA[0–31]
65