TC94A48FG Datasheet, PDF (14/36 Pages) Toshiba Semiconductor – Single-chip Audio Digital Signal Processor

TC94A48FG
2.1 Normal Transmission Mode
2.1.1 Data Transfer Format in Normal Transmission Mode
Figure 1 shows the data transfer format in normal transmission mode.
In normal transmission mode, the system first drives /MICS low and then checks that /MIACK is low
before transferring a 24-bit command MSB first. It cannot transfer data if /MIACK is high.
The system then reads or writes as many 24-bit data words (one to eight) as specified with the 24-bit
command and finally drives /MICS high. For a read, it should also make sure that /MIACK is low
after transferring a 24-bit command because /MIACK becomes high temporarily after the command is
transferred.
24bit DATA(1～8word)
/MICS
/MIACK
/MILP
/MICK
/MIDIO
COMMAND(24bit)
DATA(24bit)
DATA(24bit)
Figure 5(a) Data Transfer Format in Normal Transmission Mode
2.1.2 Data Transfer Method in Normal Transmission Mode
(1) Program boot and program start
The TC94A48FG has 1k-word RAM assigned to program addresses 000h to 3FFh, in which 000h to
003h are interrupt vector addresses. To enable the TC94A48FG to operate, a program must be booted
to an interrupt vector address. If you want to store a program in the area from 004h to 3FFh, a
program loading process must follow the interrupt vector address. For a program boot, the 24-bit
command transferred upon a reset must have the program RAM boot start bit and soft reset bit set to
"1" (command = xxxx60h).
The command must be followed by 16-bit program data, set in lower bits in 24-bit data.
The write address is automatically incremented (by one) from the command (000h). The program boot
completes once /MICS is driven high upon transferring the required number of words.
The write address for a program boot always starts from the command (000h). To start the program,
transfer a 24-bit command with the soft reset bit cleared and then drive /MICS high without
transferring data.
Figure 6 shows the program boot and program start procedure.
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2005-09-28