User manual

Rev. 1.00, 05/04, page 380 of 544
Table 15.2 Register Selection
I/O Address
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Transfer
Cycle
Host Register Selection
Bit 4 Bit 3 0 Bit 1 0 I/O write IDR3 write, C/D3 ← 0
Bit 4 Bit 3 1 Bit 1 0 I/O write IDR3 write, C/D3 ← 1
Bit 4 Bit 3 0 Bit 1 0 I/O read ODR3 read
Bit 4 Bit 3 1 Bit 1 0 I/O read STR3 read
Bit 4 0 0 0 0 I/O write TWR0MW write
0 0 0 1 Bit 4
1 1 1 1
I/O write TWR1 to TWR15 write
Bit 4 0 0 0 0 I/O read TWR0SW read
0 0 0 1 I/O read
Bit 4
1 1 1 1
TWR1 to TWR15 read
15.3.4 Input Data Registers 1 to 3 (IDR1 to IDR3)
The IDR registers are 8-bit read-only registers for the slave processor (this LSI), and 8-bit write-
only registers for the host processor. The registers selected from the host according to the I/O
address are shown in the following table. For information on IDR3 selection, see section 15.3.3,
LPC Channel 3 Address Register (LADR3). Data transferred in an LPC I/O write cycle is written
to the selected register. The state of bit 2 of the I/O address is latched into the C/D bit in STR, to
indicate whether the written information is a command or data. The initial values of IDR1 to IDR3
are undefined.
I/O Address
Bits 15 to 4 Bit 3 Bit 2 Bit 1 Bit 0
Transfer
Cycle
Host Register Selection
0000 0000 0110 0 0 0 0 I/O write IDR1 write, C/D1 ← 0
0000 0000 0110 0 1 0 0 I/O write IDR1 write, C/D1 ← 1
0000 0000 0110 0 0 1 0 I/O write IDR2 write, C/D2 ← 0
0000 0000 0110 0 1 1 0 I/O write IDR2 write, C/D2 ← 1