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Figures 4-21 shows the timing charts of the TOH and POH insert interface.
The µPD98413 outputs a 19.44-MHz clock resulting from dividing the 622.08-MHz clock generated by the internal
clock synthesizer by 32 from TOHCK. The µPD98413 outputs a pulse from TTOHFP (TPOHFP) to inform the
external OH input controller (peripheral device) of when to start TOH (POH) data insertion.
transmission, TTOHFP is held high for one cycle from the second last rising edge of the last row of the previous
frame. TPOHFP is held high for one cycle from the second last rising edge of the last Z0 byte on TOH.
The external OH input controller samples TTOHFP and TPOHFP at the rising edge of the clock. If it detects
TTOHFP is high, the TOH data is input sequentially, starting from the first A1 byte, to TOHD [1:0] in sync with the
next rising edge. If it detects TPOHFP is high, the POH data is input sequentially, starting from the J1 byte, to
TOHD [1:0] in sync with the next rising edge.
As TOH (POH) data, one byte is input to the 2-bit parallel data lines TOHD [1:0] in 4 clock cycles. The
µPD98413 samples and inputs TOHD [1:0] at the rising edge of TOHCK.
TOHAV is a signal by which the µPD98413 is informed it the external OH input controller is outputting valid data
to TOHD [1:0]. The µPD98413 samples TOHAV at the clock edge of the first of the 4 cycles in which the one
byte is input. While TOHAV is high, the bytes are input; while it is low, the bytes are ignored. TOHAV is ignored
at the edge of the next three cycles.
The insertion timing of the TOH information is allocated to all the TOH bytes of 36 bytes × 9 rows. However, the
TOH bytes shown in Table 4-5 cannot be changed by the TOH insert interface because the µPD98413 internally
overwrites them for transmission even if they are inserted as valid data by driving TOHAV high.
The insertion timing is allocated to the nine bytes of the POH information. However, the POH bytes shown in
Table 4-5 cannot be updated by the POH insert interface because it is internally overwritten by the µPD98413
even if valid data is inserted by driving TPOHAV high.
The OH bytes inputs as valid bytes from the TOH and POH insert interfaces are transmitted, taking precedence
over the setting of the insert register and transmission of the J0 and J1 trace messages.
However, because the internal processing of the µPD98413, such as the transmission of BIP and REI and the
transmission of a pointer, takes precedence, some bytes may be overwritten even if they are input from the insert
interface.
Low
OH insert register
trace message
transmission command
CHAPTER 4 INTERFACES
J0, J1 byte
OH insert interface
Section and Line DCC
PRELIMINARY
Priority
insert interface
NEC confidential and Proprietary
In normal
High
µ
Internal processing of
PD98413
• BIP, REI processing
• Pointer processing
• Transmission of alarm
141
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