5 serial interface operations – Philips TDA5360 User Manual
Page 16
1998 July 30
Philips Semiconductors
Objective Specification, Revision 2.2
Pre-Amplifier for Hard Disk Drive with
MR-Read / Inductive Write Heads
TDA5360
16
10.5
Serial Interface Operations
The serial interface communication consists of an adress word of 8 bits followed by a data word of 8 bits. See section
11, page 24 and 25 for timing diagrams.
10.5.1 S
ERIAL
ADDRESSING
When SEN goes HIGH, bits are latched-in at rising edges of SCLK. The first eight bits a7-a0 starting with the LSB, are
shifted serially into an address register.
If SEN goes LOW before 16 bits have been found, then the operation is ignored.
When STWn is HIGH; if a1 does not match CS0 or a2 does not match CS1, then the operation is ignored.
When STWn is LOW; if a1 and a2 are not HIGH, then the operation is ignored.
Bits a3 to a6 constitute the register address. Bit a7 is an unused one.
If
(a0, a1, a2, STWn) = (0, CS0, CS1, 1)
or if
(a0, a1, a2, STWn) = (0, 1, 1, 0)
then a PROGRAMMING sequence starts (see Reg. 09 description for details about preamp addressing)
If
(a0, a1, a2, STWn) = (1, CS0, CS1, 1)
or if
(a0, a1, a2, STWn) = (1, 1, 1, 0)
then READING data from the pre-amplifier can start. The data read back can be either 3.3V compatible or 5V
compatible depending on SIOLV bit in Reg. 09.
10.5.2 P
ROGRAMMING
DATA
During a programming sequence, the last eight bits d0-d7, before SEN goes LOW, are shifted into an input register.
When SEN goes LOW, the communication sequence is ended and the data in the input register are copied in parallel to
the data register corresponding to the decoded address a6-a3. SEN should go LOW at least 5ns after the last rising
edge of SCLK.
10.5.3 R
EADING
DATA
Immediately after the IC detects a reading sequence, data from the data register (address a6-a3) are copied
in parallel to the input register. The LSB d0 is placed on SDATA line followed by d1 at the
next falling edge of SCLK, etc...
If SEN goes LOW before 8 address bits (a7-a0) have been detected, the communication is ignored. If SEN goes LOW
before the 8 data bits have been sent out of the IC, the reading sequence is immediately interrupted.
SEN must stay LOW at least 75ns between two adressings.
See Timing diagramms for Serial Adressing on section 11.
10.5.4 B
ROADCAST
MODE
When A1=A2=1 and STWN=LOW, all the preamps will be adressed whatever their CS1/CS0 setup is.
This mode allows parallel programming of any register of the serial interface, and allows STW mode programming (See
Reg. 09 description).