Datasheet

ADSP-2186
–5–
REV. B
Pin Terminations (Continued)
I/O Hi-Z*
Pin 3-State Reset Caused Unused
Name (Z) State By Configuration
D4 or I/O (Z) Hi-Z BR, EBR Float
IS I I High (Inactive)
D3 or I/O (Z) Hi-Z BR, EBR Float
IACK Float
D2:0 or I/O (Z) Hi-Z BR, EBR Float
IAD15:13 I/O (Z) Hi-Z IS Float
PMS O (Z) O BR, EBR Float
DMS O (Z) O BR, EBR Float
BMS O (Z) O BR, EBR Float
IOMS O (Z) O BR, EBR Float
CMS O (Z) O BR, EBR Float
RD O (Z) O BR, EBR Float
WR O (Z) O BR, EBR Float
BR I I High (Inactive)
BG O (Z) O EE Float
BGH O O Float
IRQ2/PF7 I/O (Z) I Input = High (Inactive)
or Program as Output,
Set to 1, Let Float
IRQL1/PF6 I/O (Z) I Input = High (Inactive)
or Program as Output,
Set to 1, Let Float
IRQL0/PF5 I/O (Z) I Input = High (Inactive)
or Program as Output,
Set to 1, Let Float
IRQE/PF4 I/O (Z) I Input = High (Inactive)
or Program as Output,
Set to 1, Let Float
SCLK0 I/O I Input = High or Low,
Output = Float
RFS0 I/O I High or Low
DR0 I I High or Low
TFS0 I/O O High or Low
DT0 O O Float
SCLK1 I/O I Input = High or Low,
Output = Float
RFS1/IRQ0 I/O I High or Low
DR1/FI I I High or Low
TFS1/IRQ1 I/O O High or Low
DT1/FO O O Float
EE I I
EBR II
EBG OO
ERESET II
EMS OO
EINT II
ECLK I I
ELIN I I
ELOUT O O
NOTES
*Hi-Z = High Impedance.
1. If the CLKOUT pin is not used, turn it OFF, using CLKODIS in SPORT0
autobuffer control register.
2. If the Interrupt/Programmable Flag pins are not used, there are two options:
Option 1: When these pins are configured as INPUTS at reset and function as
interrupts and input flag pins, pull the pins High (inactive).
Option 2: Program the unused pins as OUTPUTS, set them to 1, and let them
float.
3. All bidirectional pins have three-stated outputs. When the pins are configured
as an output, the output is Hi-Z (high impedance) when inactive.
4. CLKIN, RESET, and PF3:0 are not included in the table because these pins
must be used.
Setting Memory Mode
Memory Mode selection for the ADSP-2186 is made during
chip reset through the use of the Mode C pin. This pin is multi-
plexed with the DSP’s PF2 pin, so care must be taken in how
the mode selection is made. The two methods for selecting the
value of Mode C are passive and active.
Passive configuration involves the use of a pull-up or pull-down
resistor connected to the Mode C pin. To minimize power
consumption, or if the PF2 pin is to be used as an output in the
DSP application, a weak pull-up or pull-down, on the order of
100 k, can be used. This value should be sufficient to pull the
pin to the desired level and still allow the pin to operate as a
programmable flag output without undue strain on the processor’s
output driver. For minimum power consumption during
power-down, reconfigure PF2 to be an input, as the pull-up or
pull-down will hold the pin in a known state, and will not switch.
Active configuration involves the use of a three-stateable exter-
nal driver connected to the Mode C pin. A driver’s output en-
able should be connected to the DSP’s RESET signal such that
it only drives the PF2 pin when RESET is active (low). After
RESET is deasserted, the driver should three-state, thus allow-
ing full use of the PF2 pin as either an input or output.
To minimize power consumption during power-down, configure
the programmable flag as an output when connected to a three-
stated buffer. This ensures that the pin will be held at a constant
level and not oscillate should the three-state driver’s level hover
around the logic switching point.
Interrupts
The interrupt controller allows the processor to respond to the
eleven possible interrupts and reset with minimum overhead.
The ADSP-2186 provides four dedicated external interrupt
input pins, IRQ2, IRQL0, IRQL1 and IRQE (shared with the
PF7:4 pins). In addition, SPORT1 may be reconfigured for
IRQ0, IRQ1, FI and FO, for a total of six external interrupts.
The ADSP-2186 also supports internal interrupts from the
timer, the byte DMA port, the two serial ports, software and the
power-down control circuit. The interrupt levels are internally
prioritized and individually maskable (except power-down and
RESET). The IRQ2, IRQ0 and IRQ1 input pins can be pro-
grammed to be either level- or edge-sensitive. IRQL0 and IRQL1
are level-sensitive and IRQE is edge-sensitive. The priorities and
vector addresses of all interrupts are shown in Table I.
Table I. Interrupt Priority and Interrupt Vector Addresses
Source Of Interrupt Interrupt Vector Address (Hex)
Reset (or Power-Up with
PUCR = 1) 0000 (Highest Priority)
Power-Down (Nonmaskable) 002C
IRQ2 0004
IRQL1 0008
IRQL0 000C
SPORT0 Transmit 0010
SPORT0 Receive 0014
IRQE 0018
BDMA Interrupt 001C
SPORT1 Transmit or IRQ1 0020
SPORT1 Receive or IRQ0 0024
Timer 0028 (Lowest Priority)