
Philips Semiconductors
Product specification
SC28L92
3.3V–5.0V Dual Universal Asynchronous
Receiver/Transmitter (DUART)
2000 Jan 21
26
CSR CLOCK SELECT REGISTER
Addr
CSR (7:4)
CSR (3:0)
CSRA/B
RECEIVER CLOCK SELECT
TRANSMITTER CLOCK SELECT
0x01
0x09
See Text and table 5
See Text and table 5
Table 5. Baud rate (base on a 3.6864MHz crystal clock)
MR0[0] = 0 (Normal Mode)
MR0[0] = 1 (Extended Mode I)
MR0[2] = 1 (Extended Mode II)
CSRA[7:4]
ACR[7] = 0
ACR[7] = 1
ACR[7] = 0
ACR[7] = 1
ACR[7] = 0
ACR[7] = 1
0000
50
75
300
450
4,800
7,200
0001
110
110
110
110
880
880
0010
134.5
134.5
134.5
134.5
1,076
1,076
0011
200
150
1200
900
19.2K
14.4K
0100
300
300
1800
1800
28.8K
28.8K
0101
600
600
3600
3600
57.6K
57.6K
0110
1,200
1,200
7200
7,200
115.2K
115.2K
0111
1,050
2,000
1,050
2,000
1,050
2,000
1000
2,400
2,400
14.4K
14.4K
57.6K
57.6K
1001
4,800
4,800
28.8K
28.8K
4,800
4,800
1010
7,200
1,800
7,200
1,800
57.6K
14.4K
1011
9,600
9,600
57.6K
57.6K
9,600
9,600
1100
38.4K
19.2K
230.4K
115.2K
38.4K
19.2K
1101
Timer
Timer
Timer
Timer
Timer
Timer
1110
IP4–16X
IP4–16X
IP4–16X
IP4–16X
IP4–16X
IP4–16X
1111
IP4–1X
IP4–1X
IP4–1X
IP4–1X
IP4–1X
IP4–1X
NOTE:
The receiver clock is always a 16X clock except for CSRA[7:4] = 1111.
CSRA[3:0]—Channel A Transmitter Clock Select
This field selects the baud rate clock for the Channel A transmitter.
The field definition is as shown in Table 5, except as follows:
CSRA[3:0]
1110
1111
IP3–16X
IP3–1X
The transmitter clock is always a 16X clock except for
CSR[3:0] = 1111.
CSRB—Channel B Clock Select Register
CSRB[7:4]—Channel B Receiver Clock Select
This field selects the baud rate clock for the Channel B receiver. The
field definition is as shown in Table 5, except as follows:
CSRB[7:4]
1110
1111
IP6–1X
IP6–16X
The receiver clock is always a 16X clock except for
CSRB[7:4] = 1111.
CSRB[3:0]—Channel B Transmitter Clock Select
This field selects the baud rate clock for the Channel B transmitter.
The field definition is as shown in Table 5, except as follows:
CSRB[3:0]
1110
1111
IP5–1X
IP5–16X
The transmitter clock is always a 16X clock except for
CSRB[3:0] = 1111.