Datasheet

Rev. C | Page 18 of 48 | December 2006
ADSP-TS202S
Table 12. Pin Definitions—Impedance Control, Drive Strength Control, and Regulator Enable
Signal Type Term Description
CONTROLIMP0
CONTROLIMP1
I (pd)
I (pu)
na
na
Impedance Control. As shown in Table 13, the CONTROLIMP1–0 pins select between
normal driver mode and A/D driver mode. When using normal mode (recommended),
the output drive strength is set relative to maximum drive strength according to
Table 14. When using A/D mode, the resistance control operates in the analog mode,
where drive strength is continuously controlled to match a specific line impedance as
shown in Table 14.
DS2,
DS1
I (pu)
I (pd)
na Digital Drive Strength Selection. Selected as shown in Table 14. For drive strength calcu-
lation, see Output Drive Currents on Page 36. The drive strength for some pins is preset,
not controlled by the DS2–0 pins. The pins that are always at drive strength 7 (100%)
include: CPA
, DPA, TDO, EMU, and RST_OUT. The drive strength for the ACK pin is always
x2 drive strength 7 (100%).
ENEDREG I (pu) V
SS
Connect the ENEDREG pin to V
SS
. Connect the V
DD_DRAM
pins to a properly decoupled
DRAM power supply.
I = input; A = asynchronous; O = output; OD = open-drain output; T = three-state; P = power supply; G = ground; pd = internal pull-down
5k
Ω; pu = internal pull-up 5 kΩ; pd_0 = internal pull-down 5 kΩ on DSP ID = 0; pu_0 = internal pull-up 5 kΩ on DSP ID = 0; pu_od_0 = internal
pull-up 500 Ω on DSP ID = 0; pd_m = internal pull-down 5 kΩ on DSP bus master; pu_m = internal pull-up 5 kΩ on DSP bus master; pu_ad
= internal pull-up 40 k
Ω. For more pull-down and pull-up information, see Electrical Characteristics on Page 22.
Term (termination of unused pins) column symbols: epd = external pull-down approximately 5 k
Ω to V
SS
; epu = external pull-up approx-
imately 5 kΩ to V
DD_IO
, nc = not connected; na = not applicable (always used); V
DD_IO
= connect directly to V
DD_IO
; V
SS
= connect directly to V
SS
Table 13. Impedance Control Selection
CONTROLIMP1-0 Driver Mode
00 (recommended) Normal
01 Reserved
10 (default) A/D Mode
11 Reserved
Table 14. Drive Strength/Output Impedance Selection
DS2–0
Pins
Drive
Strength
1
Output
Impedance
2
000 Strength 0 (11.1%) 26 Ω
001 Strength 1 (23.8%) 32 Ω
010 Strength 2 (36.5%) 40 Ω
011 Strength 3 (49.2%) 50 Ω
100 Strength 4 (61.9%) 62 Ω
101 (default) Strength 5 (74.6%) 70 Ω
110 Strength 6 (87.3%) 96 Ω
111 Strength 7 (100%) 120 Ω
1
CONTROLIMP1 = 0, A/D mode disabled.
2
CONTROLIMP1 = 1, A/D mode enabled.