Datasheet

Rev. B | Page 14 of 68 | March 2013
ADSP-21483/ADSP-21486/ADSP-21487/ADSP-21488/ADSP-21489
PIN FUNCTION DESCRIPTIONS
Table 11. Pin Descriptions
Name Type
State
During/
After Reset Description
ADDR
23–0
I/O/T (ipu) High-Z/
driven low
(boot)
External Address. The processor outputs addresses for external memory and periph-
erals on these pins. The ADDR pins can be multiplexed to support the external memory
interface address, and FLAGS15–8 (I/O) and PWM (O). After reset, all ADDR pins are in
external memory interface mode and FLAG(0–3) pins are in FLAGS mode (default).
When configured in the IDP_PDAP_CTL register, IDP channel 0 scans the ADDR
23–4
pins
for parallel input data.
DATA
15–0
I/O/T (ipu) High-Z External Data. The data pins can be multiplexed to support the external memory
interface data (I/O), and FLAGS
7–0
(I/O).
AMI_ACK I (ipu) Memory Acknowledge. External devices can deassert AMI_ACK (low) to add wait
states to an external memory access. AMI_ACK is used by I/O devices, memory
controllers, or other peripherals to hold off completion of an external memory access.
MS
0–1
O/T (ipu) High-Z Memory Select Lines 0–1. These lines are asserted (low) as chip selects for the corre-
sponding banks of external memory. The MS
1-0
lines are decoded memory address lines
that change at the same time as the other address lines. When no external memory
access is occurring the MS
1-0
lines are inactive; they are active however when a condi-
tional memory access instruction is executed, when the condition evaluates as true.
The MS1
pin can be used in EPORT/FLASH boot mode. For more information, see the
ADSP-214xx SHARC Processor Hardware Reference.
AMI_RD
O/T (ipu) High-Z AMI Port Read Enable. AMI_RD is asserted whenever the processor reads a word from
external memory.
AMI_WR
O/T (ipu) High-Z AMI Port Write Enable. AMI_WR is asserted when the processor writes a word to
external memory.
FLAG0/IRQ0
I/O (ipu) FLAG[0]
INPUT
FLAG0/Interrupt Request0.
FLAG1/IRQ1 I/O (ipu) FLAG[1]
INPUT
FLAG1/Interrupt Request1.
FLAG2/IRQ2
/MS2 I/O (ipu) FLAG[2]
INPUT
FLAG2/Interrupt Request2/Memory Select2.
FLAG3/TMREXP/MS3
I/O (ipu) FLAG[3]
INPUT
FLAG3/Timer Expired/Memory Select3.
The following symbols appear in the Type column of this table: A = asynchronous, I = input, O = output, S = synchronous, A/D = active drive,
O/D = open drain, and T = three-state, ipd = internal pull-down resistor, ipu = internal pull-up resistor.
The internal pull-up (ipu) and internal pull-down (ipd) resistors are designed to hold the internal path from the pins at the expected logic
levels. To pull-up or pull-down the external pads to the expected logic levels, use external resistors. Internal pull-up/pull-down resistors cannot
be enabled/disabled and the value of these resistors cannot be programmed. The range of an ipu resistor can be between 26 kΩ–63 kΩ. The
range of an ipd resistor can be between 31 kΩ–85kΩ. The three-state voltage of ipu pads will not reach to the full V
DD_EXT
level; at typical
conditions the voltage is in the range of 2.3 V to 2.7 V.
In this table, all pins are LVTTL compliant with the exception of the thermal diode pins.