Filter
Top Products
Input Data From Port
IN
7-69
Assembly Language Instructions
Syntax IN
dma
,
PA
Direct addressing
IN
ind
,
PA
[, AR
n
] Indirect addressing
Operands dma: 7 LSBs of the data-memory address
n: Value from 0 to 7 designating the next auxiliary register
PA: 16-bit I/O port or I/O-mapped register address
ind: Select one of the following seven options:
* *+ *– *0+ *0– *BR0+ *BR0–
IN
dma , PA
1514131211109876543210
1
01011110 dma
PA
IN
ind ,PA
[
,
AR
n
]
1514131211109876543210
1
01011111 ARU N NAR
PA
Note: ARU, N, and NAR are defined in Section 6.3,
Indirect Addressing Mode
(page 6-9).
Execution Increment PC, then ...
PA → address bus lines A15–A0
Data bus lines D15–D0 → data-memory address
(PA) → data-memory address
Status Bits None
Description The IN instruction reads a 16-bit value from an I/O location into the specified
data-memory location. The IS
line goes low to indicate an I/O access. The
STRB
, RD, and READY timings are the same as for an external data-memory
read.
The repeat (RPT) instruction can be used with the IN instruction to read in con-
secutive words from I/O space to data space.
Words 2
Opcode