CMX813 Просмотр технического описания (PDF) - MX-COM Inc
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CMX813 Datasheet PDF : 19 Pages
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CMX813 Multi-Standard Analog Paging Decoder
8
5.1.3 8-bit Read Only Registers
CMX813 Advance Information
HEX
ADDRESS/
COMMAND
$38
REGISTER
NAME
DECODED
TONE
ADDRESS
$3F
STATUS
BIT 7
(D7)
BIT 6
(D6)
BIT 5
(D5)
BIT 4
(D4)
BIT 3
(D3)
BIT 2
(D2)
BIT 1
(D1)
BIT 0
(D0)
MSB
BIT 7
BIT6
BIT 5
Reserved set to
1
1
0
DECODED TONE ADDRESS
BIT 4
RAM
FULL
BIT 3
DECODE
STATUS
CHANGE
BIT 2
TONE
DECODE
LSB
BIT 1
BIT 0
DECODED ROM PAGE
MSB
LSB
BIT 1
BIT 0
5.1.4 Read Only Register Description
5.1.4.1 DECODED TONE ADDRESS Register (Hex address $38)
This register is used to send the decoded ROM addresses to the host micro as described below:
DECODED
TONE ADDRESS
(Bits 7, 6, 5, 4, 3, 2, 1,
and 0)
When a tone is decoded, the CMX813 generates an interrupt and reports the
decoded tone table 8-bit ROM address. The tone table and address allocations
are listed in the Application Notes, Section 1.6.
For the 1-tone or 2-tone system, the 8-bit ROM address is located either from
ROM PAGE 1 or 2.
For the 5/6 tone and HSC tones system, Bits 7, 6, 5, and 4 represent the
selected tone set (CCIR/ZVEI etc), Bits 3, 2, 1, and 0 are the 4 bit Hexadecimal
tone value within the selected group. This is located in ROM PAGE 3.
5.1.4.2 STATUS Register (Hex address $3F)
This register is used to indicate the status of the device as described below:
(Bits 7, 6 and 5)
RAM FULL
(Bit 4)
DECODE STATUS
CHANGE
(Bit 3)
TONE DECODE
(Bit 2)
DECODED ROM
PAGE
(Bits 1 and 0)
Reserved for future use. These will be set to "110" respectively but should be
ignored by user's software.
After eight tone addresses are loaded to the RAM for tones located in ROM
PAGE 1 or 2, this bit is set to ‘1’. A Clear RAM command will reset it to ‘0’.
When TONE DECODE (Bit 2 of this register) or the decoded 8 bit address in
DECODED TONE ADDRESS Register $38 changes state this bit will be set to
"1". A “0” indicates no decode status change.
This bit indicates the status of the tone decoder. A "1" indicates a tone has been
detected (TONE DECODE) and a "0" indicates the loss of the tone (NOTONE).
TONE DECODE means that a tone has been decoded and its characteristics
are as defined by the bandwidth (see CONTROL Register $30, Bits 5, 4, 3 and
2) and the center frequency (see TONE ADDRESS Register $31, Bit 7 to Bit 0).
When Bit 7 and Bit 6 in the CONTROL Register $30 are set to "0" the TONE
DECODE Bit 2 will be set to "0".
From NOTONE state, identification of a valid tone which is not in the pre-
programmed list (up to eight tones in 1 or 2 tone system and 16 tones in 5/6
tone or HSC) will cause the decoder to move to the TONE DECODE state with
the DECODED ROM PAGE address of "00" in Bits 1 and 0; indicating a valid but
unrecognized tone. No interrupt is generated.
Loss of tone will cause the NOTONE timer to be started. If loss of tone
continues for the duration of the time-out period, then the decoder will move to
the NOTONE state and the identification of pre-programmed tones will start
again. The time-out period is not user adjustable.
These two bits represent the ROM PAGE where the decoded tone is located.
¤2000 MX-COM, Inc.
www.mxcom.com tel: 336 744 5050 800 638 5577 fax: 336 744 5054
Doc. # 20480220.002
4800 Bethania Station Road, Winston-Salem, NC 27105-1201, USA All trademarks and service marks are held by their respective customers.
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