35
Single Channel Indirect Registers
TABLE 39. SINGLE CHANNEL INDIRECT REGISTER MAP
INDIRECT
ADDRESS
Page
Type
Update
strobe
Slave location
FUNCTION
000 .. 07F
0
R/W
Gain profile
080 .. 0FF
0
Not used
100 .. 1FF
1
R/W
Read I coefficients.
Write I and Q shaping filter coefficients
when I and Q are not equal.
200 .. 2FF
2
Not Used.
300 .. 3FF
3
R/W
Read Q coefficients.
Write I and Q shaping filter coefficients
when I and Q are equal.
400 .. 407
4
R/W
TXENX programmed cycle values.
408 .. 4FF
4-F
Not Used.
TABLE 40. GAIN PROFILE (15:0)
TYPE: SINGLE CHANNEL INDIRECT, ADDRESS RANGE: 0x000-0x07f (PAGE 0)
BIT
FUNCTION
DESCRIPTION
15:12
Reserved
Not Used.
11:0
Gain profile
128 location RAM that multiplies the channel gain in incremental steps at the coarse phase rate. The gain
profile is enabled by control word 0x0d[15]. The address is reset to zero on assertion of the gain profile
enable. The address is incremented by one with each change in coarse phase after assertion of the TX
enable. The address is held upon reaching the upper address used for the gain profile RAM, Gain profile
length
0x0b.
On deassertion of the TX enable the gain profile address is decremented back to zero.
Bit weight 2
0
. 2
-1
2
-2
... 2
-11
Maximum 0x800 = 1.0
0x001 = 2-11
Minimum 0x000 = 0.0
NOTES:
1. The contents of the last used location must be 0x800, (specified by the gain profile length).
Write
access to the Gain Profile RAM:
1. Enable the gain profile hold mode by setting bit 14 of the Main Control register 0x0c.
2. Load the RAM data to location 0x14.
3. Load the RAM write address to location 0x15. A write strobe transfers the contents of the register at location 0x14 into the RAM location
specified by the contents of the register at location 0x15. (Indirect address[15] =0).
4. Wait 4 clock cycles before performing the next write to the RAM data register.
5. Repeat steps 2-4.
6. Return gain control back to the channel by disabling the gain profile hold 0x0c, bit 14.
Read
access to the Gain Profile:
1. Enable the gain profile hold mode by setting bit 14 of the Main Control register 0x0c.
2. Load the RAM read address and 0x8000 to location 0x15. A read strobe transfers the contents of the RAM location specified by the contents
of the register at location 0x15 onto the read bus. (Indirect address[15] =1, Indirect address[9:8] =’00’).
3. Wait 4 clock cycles before performing the next write to the RAM address register.
4. Repeat steps 2-3.
5. Return gain control back to the channel by disabling the gain profile hold 0x0c, bit 14.
ISL5217