TDA9950TT/C2,518 NXP Semiconductors, TDA9950TT/C2,518 Datasheet - Page 8

• Manufacturer Part Number: TDA9950TT/C2,518
• Manufacturer: NXP Semiconductors

Specifications of TDA9950TT/C2,518

• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Package Type: TSSOP
• Pin Count: 20
• Mounting: Surface Mount
• Lead Free Status / Rohs Status: Compliant

NXP Semiconductors
TDA9950_2
Product data sheet
8.5 Data register protocol
Table 13.
Table 14.
Communication between the TDA9950 and the host using the CEC Data Registers is
carried out using frames of information. The host is the master of all data transfers; the
TDA9950 uses the INT line to inform the host that it has data available.
Before a frame is read or written, the host must set the REG_PTR field in the Address
Pointer Register to the base CEC Data Register address. Successive reads or writes
automatically increment the REG_PTR as the frame is transferred. Message transfers can
only start from the first CEC Data Register at address 07h and not from higher addresses,
as messages must be transferred complete and not in fragments.
Each frame consists of a byte count, a service selector and then zero or more (up to 17)
parameters as shown in
The FrameByteCount indicates the number of bytes in the frame (including the
FrameByteCount itself). The service is specified by the ServiceSelector (see
The remaining bytes of the frame, if any, contain the parameters associated with a
particular service. The maximum length of a frame is 19 bytes. The TDA9950 will only
accept a single outstanding request. Reading message bytes beyond FrameByteCount
will return FFh.
Table 15
ServiceSelector is sent to the TDA9950 it will respond with the confirmation Bad .req
service (see
sections are mandatory. No service contains optional parameters.
Bit
4
3
2 to 0
Bit
7 to 0
Fig 3.
shows the organization of the ServiceSelector values. If an unused
Symbol
ENABLE_ERROR
-
RETRY[2:0]
Symbol
FrameByteCount/
ServiceSelector/
Parameters[7:0]
Frame format for the data register protocol
CCONR - CEC Configuration Register (address 06h) bit description (Read/Write)
CDR[0:18] - CEC Data Registers (addresses 07h to 19h) bit description
(Read/Write)
Table
FrameByteCount
17). For every service, the parameters that are defined in the following
Register CDR0
Rev. 02 — 22 October 2009
Figure
3.
Description
ENABLE_ERROR:
0 = no specific action.
1 = notify the host of all errors via the TDA9950 Error Register
and via the CECData.err service (see
not used
RETRY[2:0]: retry count to be used by the TDA9950. The
maximum value is 5; values greater than 5 will still give 5
retries.
Description
FrameByteCount/ServiceSelector/Parameters:
Length of message in B, Type of message, 17 B for message
content; see
ServiceSelector
Register CDR1
Section 8.5 “Data register
Register CDR2
[Parameters]
[...]
CEC/I
001aag924
Section
protocol”.
[...]
TDA9950
© NXP B.V. 2009. All rights reserved.
2
C-bus translator
8.5.4).
Table
15).
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