AK4213 Datasheet, PDF (28/38 Pages) Asahi Kasei Microsystems – Mono Class-D SPK-Amp with Stereo Cap-less HP-Amp

[AK4213]
2. READ Operations
Set the R/W bit = “1” for the READ operation of the AK4213. After transmission of data, the master can read the next
address’s data by generating an acknowledge instead of terminating the write cycle after the receipt of the first data word.
After receiving each data packet the internal 5-bit address counter is incremented, and the next data is automatically taken
into the next address. If the address exceeds 12H prior to generating stop condition, the address counter will “roll over” to
00H and the previous data will be overwritten.
The AK4213 supports two basic read operations: CURRENT ADDRESS READ and RANDOM ADDRESS READ.
2-1. CURRENT ADDRESS READ
The AK4213 contains an internal address counter that maintains the address of the last word accessed, incremented by
one. Therefore, if the last access (either a read or write) were to address “n”, the next CURRENT READ operation would
access data from the address “n+1”. After receipt of the slave address with R/W bit “1”, the AK4213 generates an
acknowledge, transmits 1-byte of data to the address set by the internal address counter and increments the internal
address counter by 1. If the master does not generate an acknowledge but generates stop condition, the AK4213 ceases
transmission.
S
T
A
R/W="1"
R
T
SDA
Slave
S _Address
A
C
K
Data(n)
Data(n+1)
Data(n+2)
MA
MA
MA
AC
AC
AC
S
T
K
S
T
K
S
T
K
E
E
E
R
R
R
S
T
O
P
Data(n+x)
P
MA
MN
AC
AA
S
T
K
E
S
T
E
C
K
R
R
Figure 24. CURRENT ADDRESS READ
2-2. RANDOM ADDRESS READ
The random read operation allows the master to access any memory location at random. Prior to issuing the slave address
with the R/W bit “1”, the master must first perform a “dummy” write operation. The master issues start request, a slave
address (R/W bit = “0”) and then the register address to read. After the register address is acknowledged, the master
immediately reissues the start request and the slave address with the R/W bit “1”. The AK4213 then generates an
acknowledge, 1 byte of data and increments the internal address counter by 1. If the master does not generate an
acknowledge to the data but generates a stop condition, the AK4213 ceases transmission.
S
T
A
R/W="0"
R
T
SDA
Slave
S _Address
Sub
Address(n)
A
C
K
S
T
A
R/W="1"
R
T
Slave
S _Address
A
A
C
C
K
K
Data(n)
Data(n+1)
MA
MA
AC
AC
S
T
K
S
T
K
E
E
R
R
S
T
O
P
Data(n+x)
P
MA
MN
AC
AA
S
T
K
S
T
C
E
EK
R
R
Figure 25. RANDOM ADDRESS READ
MS0949-E-01
- 28 -
2008/07