SM8213AM datasheet(19/33 Pages) NPC

19 / 33 page

SM8213AM

NIPPON PRECISION CIRCUITS—19

Decoder Internal Status Transfer (SM8213AM to CPU)

In the SM8213AM, the internal decoder status and

parameter/address end-of-processing conﬁrmation,

is transmitted to the CPU. The microcontroller uses

this status information only when needed.

This is a 2-byte (16 bits) command where the ﬁrst

byte is a decoder set read command and the second

byte is the decoder internal status that is sent to the

microcontroller in sync with the SCK clock.

The microcontroller can use this function when not

receiving data from the decoder (when ATTN is

HIGH only).

Note the following points when setting the read com-

mand:

When ATTN is HIGH

After data is transferred and until ATTN goes

LOW for the next transmit ready data signal, the

series processing should be such that it takes less

than {32

× (bit rate)} time. If it takes longer than

this amount of time, the command setting may be

delayed (relative to normal operation) when ATTN

goes LOW. Note that during this time, there is no

guarantee of data.

When ATTN goes HIGH (excluding write mode),

SCK is examined to determine if the signal is a

break, back-up, write or read command. During mes-

sage reception, ATTN is temporarily held HIGH if a

command is issued to set ATTN LOW. This delay

ensures that the data from the decoder is not misin-

terpreted. And in this case, even if ATTN keeps

LOW, transmitted receiving data is unstable.

Figure 11. Internal status transfer timing

ATTN

SCK

SDO

SDI

8-bit

× 2-byte = 16-bit unit time clock

8-bit

× 1-byte = 8-bit unit time data

8-bit

× 1-byte = 8-bit unit time indeterminate data

READ

STATUS DATA

Refer to the AC Characteristics section for detailed timing specifications.

Indicates indeterminate data output.

When the CPU interprets the internal status,

these portions can be ignored (discarded).

SM8213AM Arkusz danych(PDF) 19 Page - Nippon Precision Circuits Inc

SM8213AM Arkusz danych(HTML) 19 Page - Nippon Precision Circuits Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Arkusz danych Pobierz

Link URL