SAA7109 PHILIPS [NXP Semiconductors], SAA7109 Datasheet - Page 93

• Manufacturer Part Number: SAA7109
• Description: PC-CODEC
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
10.3
A crystal accurate frequency reference is required for the
generation of the line-locked video (pixel) clock LLC, and
the frame-locked audio serial bit clock. An oscillator is
built-in, for fundamental or 3rd-harmonic crystals. The
supported crystal frequencies are 32.11 or 24.576 MHz
(defined during reset by strapping pin ALRCLK).
Alternatively pins XTALId and XTALIe can be driven from
an external single-ended oscillator.
The crystal oscillation can be propagated as clock to other
ICs in the system via pin XTOUTd.
Table 56 Clock and real-time synchronization signals
2004 Mar 16
Crystal oscillator
XTALId
XTALOd
XTOUTd
Real-time signals (RT port)
LLC
LLC2
RTCO
RTS0
RTS1
SYMBOL
PC-CODEC
Clock and real-time synchronization signals
M14
K13
PIN
L14
L13
L10
P2
P3
P4
I/O
O
O
O
O
O
O
O
I
input for crystal oscillator, or reference clock
output of crystal oscillator
reference (crystal) clock output drive (optional)
line-locked clock; nominal 27 MHz, double pixel clock locked to the
selected video input signal
line-locked pixel clock; nominal 13.5 MHz
real-time control output; transfers real-time status information
supporting RTC level 3.1 (see external document “RTC Functional
Description” , available on request)
real-time status information line 0; can be programmed to carry
various real-time informations; see Table 167
real-time status information line 1; can be programmed to carry
various real-time informations; see Table 168
DESCRIPTION
93
The Line-Locked Clock (LLC) is the double pixel clock at a
nominal 27 MHz. It is locked to the selected video input,
generating baseband video pixels according to “ITU
recommendation 601” . In order to support interfacing
circuits, a direct pixel clock LLC2 is also provided.
The pins for line and field timing reference signals are
RTCO, RTS1 and RTS0. Various real-time status
information can be selected for the RTS pins. The signals
are always available (output) and reflect the
synchronization operation of the decoder part in the
SAA7108E; SAA7109E. The function of the RTS1 and
RTS0 pins can be defined by bits RTSE1[3:0] 12H[7:4] and
RTSE0[3:0] 12H[3:0]; see Table 56.
SAA7108E; SAA7109E
XTOUTE[14H[3]]
RTSE0[3:0] 12H[3:0]
RTSE1[3:0] 12H[7:4]
Product specification
BIT