OXCF950 datasheet(42/66 Pages) OXFORD

42 / 66 page

DS-0027 Feb 06

External—Free Release

Page 42 of 66

OXCF950 rev B DATA SHEET

OXFORD SEMICONDUCTOR, INC.

logic 1

⇒ Data will be transmitted and received in IrDA

format.

This function is only available in Enhanced mode. It

requires a 16x clock to function correctly.

MCR[7]: Baud rate prescaler select

logic 0

⇒ Normal (divide by 1) baud rate generator

prescaler selected.

logic 1

⇒ Divide-by-“M N/8” baud rate generator

prescaler selected.

Where M & N are programmed in CPR (ICR offset 0x01).

After a hardware reset, CPR defaults to 0x20 (divide-by-4)

and MCR[7] is reset to ‘0’. User writes to this flag will only

take effect in enhanced mode. See section 6.9.1.

6.7.2

Modem Status Register ‘MSR’

MSR[0]: Delta CTS#

Indicates that the CTS# input has changed since the last

time the MSR was read.

MSR[1]: Delta DSR#

Indicates that the DSR# input has changed since the last

time the MSR was read.

MSR[2]: Trailing edge RI#

Indicates that the RI# input has changed from low to high

since the last time the MSR was read.

MSR[3]: Delta DCD#

Indicates that the DCD# input has changed since the last

time the MSR was read.

MSR[4]: CTS

This bit is the complement of the CTS# input. It is

equivalent to RTS (MCR[1]) during internal loop-back

mode.

MSR[5]: DSR

This bit is the complement of the DSR# input. It is

equivalent to DTR (MCR[0]) during internal loop-back

mode.

MSR[6]: RI

This bit is the complement of the RI# input. In internal loop-

back mode it is equivalent to the internal OUT1.

MSR[7]: DCD

This bit is the complement of the DCD# input. In internal

loop-back mode it is equivalent to the internal OUT2.

6.8

Other Standard Registers

6.8.1

Divisor Latch Registers ‘DLL & DLM’

The divisor latch registers are used to program the baud

rate divisor. This is a value between 1 and 65535 by which

the input clock is divided by in order to generate serial

baud rates. After a hardware reset, the baud rate used by

the transmitter and receiver is given by:

Divisor

InputClock

Baudrate

Where divisor is given by DLL + ( 256 x DLM ). More

flexible baud rate generation options are also available.

See section 6.10 for full details.

6.8.2

Scratch Pad Register ‘SPR’

The scratch pad register does not affect operation of the

rest of the UART in any way and can be used for

temporary data storage. The register may also be used to

define an offset value to access the registers in the

Indexed Control Register set. For more information on

Indexed Control registers see Table 27 and section 6.11.

6.9

Automatic Flow Control

Automatic in-band flow control, automatic out-of-band flow

control and special character detection features can be

used when in Enhanced mode and are software compatible

with the 16C654. Alternatively, 16C750 compatible

automatic out-of-band flow control can be enabled when in

non-Enhanced mode. In 950 mode, in-band and out-of-

band flow controls are compatible with 16C654, with the

addition of fully programmable flow control thresholds.

6.9.1

Enhanced Features Register ‘EFR’

Writing 0xBF to LCR enables access to the EFR and other

Enhanced mode registers. This value corresponds to an

unused data format. Writing 0xBF to LCR will set LCR[7]

but leaves LCR[6:0] unchanged. Therefore, the data format

of the transmitter and receiver data is not affected. Write

the desired LCR value to exit from this selection.

OXCF950 Datasheet(PDF) 42 Page - Oxford Semiconductor

OXCF950 Datasheet(HTML) 42 Page - Oxford Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

Datasheet Download

Link URL