UPD98404 Datasheet, PDF (11/36 Pages) NEC – ADVANCED ATM SONET FRAMER

µPD98404
Pin name Pin No.
TxFP
14
I/O level
TTL*
TFSS
13
TTL*
RCL
75
TTL*
TCL
15
TTL*
(3/3)
I/O
Function
O Frame pulse signal output for the transmit side (8 kHz). This pin
outputs a pulse signal at one-clock intervals in sync with the TCL
clock.
I Transmit frame output disable signal input. When the signal is high,
the transmit frame output stops. When the signal is low, transmission
starts from the beginning of a frame. The µPD98404 samples this
signal at the rising edge of the TCL clock. The transmit frame output
is resumed at the ninth rising edge of the TCL clock after the rising
edge at which the high level of this signal was last detected.
O Internal system clock output for the receive side (19.44 MHz). This
pin outputs the receive clock divided by 8. The source receive clock
depends on the selected mode, which is either the clock generated by
the internal clock recovery PLL or the clock supplied from the
RCIT/RCIC and RFC pins. Clock output from this pin is stopped while
the device is being reset.
O ^{Internal system clock output of the transmit side (19.44 MHz).}
This pin outputs the transmit clock divided by 8. The source transmit
clock depends on the selected mode, which is either the clock
generated by the internal synthesizer or the clock supplied from the
TCIT/TCIC and TFC pins. Clock output from this pin is stopped while
the device is being reset.
1.2 ATM layer interface
Pin name Pin No. I/O level
RDO0-
RDO7
130-137
TTL*
RCLK
128
TTL*
RSOC
126
TTL*
RENBL_B 127
TTL*
(1/2)
I/O
Function
O ^{Receive data output.}
(2 or 3- ^{These pins form an 8-bit data bus that outputs receive data to an ATM}
state) ^{layer device. The data is output in sync with the rising edge of the}
RCLK clock. These pins operate in two or three states, depending on
the UTOPIA interface mode.
I Receive clock input. This pin supplies a clock of up to 40 MHz for
receive data transfer.
O ^{Receive cell start position signal output.}
(2 or 3- ^{This pin outputs a signal indicating the position of the first byte of a}
state) ^{receive cell. This pin operates in two or three states, depending on}
the UTOPIA interface mode.
I ^{Receive enable signal input.}
This pin inputs a signal indicating that the ATM layer is ready to
receive data.
Data Sheet S11822EJ4V0DS00
11