LM8333EVALKIT National Semiconductor, LM8333EVALKIT Datasheet - Page 9

• Manufacturer Part Number: LM8333EVALKIT
• Description: BOARD EVALUATION LM8333
• Manufacturer: National Semiconductor

Specifications of LM8333EVALKIT

• Main Purpose: Interface, Special Purpose
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: LM8333
• Primary Attributes: Mobile I/O Companion with Key-Scan, I/O Expansion, PWM, Access.bus Host
• Secondary Attributes: Board has MCU for USB to PC GUI
• Lead Free Status / RoHS Status: Not applicable / Not applicable

RPT_FIFO_READ
READ_ERROR
9.3 HOST COMMAND EXECUTION
9.3.1 Command Structure
All communication with the LM8333 over the ACCESS.bus
interface is initiated by the host, usually in response to an in-
SET_EXT_INT
GEN_IO_OUT
GEN_IO_DIR
READ_STAT
DEBOUNCE
FIFO_READ
SCAN_REQ
GEN_IO_IN
PWM_CTL
READ_INT
PWM_LO
Function
PWM_HI
ACTIVE
0xD0
0xD1
0xE0
0xE3
0xE4
0xF0
Cmd
0x20
0x21
0x22
0x30
0x31
0x32
0x40
0x41
0x42
Dir
W
W
W
W
W
W
W
W
W
R
R
R
R
R
R
TABLE 5. Interface Commands for Controlling the LM8333
FIGURE 7. Typical Command Sequence from Host
Data Bits
128
128
16
16
8
8
8
8
8
8
8
8
8
8
8
Event Codes from
Event Codes from
nnnn nnnn
0000 nnnn
0000 nnnn
0000 nnnn
0000 0nnn
0000 nnnn
0000 00nn
000n nnnn
nnnn nnnn
0nnn nnnn
(n+1) × t
(n+1) × t
Data
FIFO
FIFO
9
C
C
terrupt request (IRQ low) asserted by the LM8333.
shows a sequence of Start conditions, slave addresses,
READ_INT command (0xD0), acknowledge cycles, data
bytes, and Stop condition for reading the interrupt code.
Read an event from the FIFO.
Maximum 14 event codes stored in the FIFO.
MSB = 1: key pressed.
MSB = 0: key released.
Repeats a FIFO read without advancing the FIFO pointer,
for example to retry a read after an error.
Maximum 14 event codes stored in the FIFO.
MSB = 1: key pressed.
MSB = 0: key released.
Default is 10 ms. Valid range 1–255.
Time ~ n × 3 ms
Read port data.
Specify port mode. (Drive 0 or 1 when the port is configured
as an output; select Hi-Z or pullup when the port is
configured as an input.)
Select port direction (input or output).
Sets the low pulse time of the PWM signal.
Sets the high pulse time of the PWM signal.
Activate, reactivate, or stop PWM.
Reads the interrupt code, acknowledges the interrupt,
deasserts the IRQ output, and clears the code.
Enables/disables external interrupts on GEN_IO_0 and
GEN_IO_1.
Status Information.
Requests rescanning the keypad (for example, after an
error was reported).
Specifies the time after the last event during which the
LM8333 stays active before entering Halt mode. The active
time must be greater than the debounce time.
Default is 500 msec
Valid range for n is 1–255
Time ~ n × 3 msec.
Reads and clears the error code.
Description
20210609
www.national.com
Figure 7