SMC Networks 486DX4 - Manual (Page 16)

AR-B1462 User¡ ¦s Guide
2-8
(9) Divisor Latch (LS, MS)
LS MS
Bit 0: Bit 0 Bit 8
Bit 1: Bit 1 Bit 9
Bit 2: Bit 2 Bit 10
Bit 3: Bit 3 Bit 11
Bit 4: Bit 4 Bit 12
Bit 5: Bit 5 Bit 13
Bit 6: Bit 6 Bit 14
Bit 7: Bit 7 Bit 15
Desired Baud Rate Divisor Used to Generate 16x Clock
300 384
600 192
1200 96
1800 64
2400 48
3600 32
4800 24
9600 12
14400 8
19200 6
28800 4
38400 3
57600 2
115200 1
Table 2-7 Serial Port Divisor Latch
2.7 PARALLEL PORT
(1) Register Address
Port Address Read/Write Register
base + 0 Write Output data
base + 0 Read Input data
base + 1 Read Printer status buffer
base + 2 Write Printer control latch
Table 2-8 Registers’ Address
(2) Printer Interface Logic
The parallel portion of the SMC37C669 makes the attachment of various devices that accept eight bits of parallel
data at standard TTL level.
(3) Data Swapper
The system microprocessor can read the contents of the printer’ s Data Latch through the Data Swapper by reading
the Data Swapper address.