Legacy-Free Keyboard/Embedded Controller with SPI and LPC Docking Interface
Chapter 9 Flash Programming Interface
9.1
Overview
The LPC47N350 8051 has read and write access to the embedded Flash ROM in a single contiguous
64k-byte page (Figure 9.12). The LPC47N350 64k Embedded Flash can be programmed by the 8051,
an external ATE Program interface, and by the LPC Host (Figure 9.12).
During normal operations, the Flash is dedicated as the 8051 Code space, the 8051 only has read
access to the Flash, and the internal 8051 memory ROM bus is not accessible. The Keyboard Controller
Bus Monitor (KCBM) function, which is controlled by the PGM and nEA pins, permits monitoring of the
internal 8051 memory ROM bus using the KBD Scan interface pins. When the KCBM is enabled, reads
from the 8051 code space and reads and writes from the 8051 data space are visible on the KCBM
interface pins. (see Section 9.8, "Keyboard Controller Bus Monitor Interface").
PGM
FLASH
PROGRAM
INTERFACE
DECODER
LPC
FLASH
ATE
FLASH
PRGM
LPC PGM
PRGM
4
8051 PGM
ACCESS
ACCESS
DEADMAN
SWITCH
DMS LED
8051
FLASH
CODE
8051
FLASH
PRGM
FETCH
ACCESS
ACCESS
64K
EMBEDDED
FLASH
EXTERNAL
FLASH
INTERFACE
nEA
Figure 9.1 Flash System Interface
Note: This figure is for illustration purposes only and is not intended to suggest specific implementation
details.
9.2
Flash Program Interface Decoder
The Flash Program Interface Decoder controls access to the 64k Embedded Flash (Figure 9.1).
The Flash configurations described below depend upon the state of the PGM and nEA pins and the
LPC PGM and 8051 PGM bits in the Flash Program register. The ATE PGM and EXT FLASH bits in
the Flash Program register reflect the state of the PGM and nEA pins. When the PGM and nEA pins
are asserted, the Flash Program Interface Decoder enters the KCBM Interface state (see Table 9.1,
"Flash Program Interface Decoder Truth Table", items# 6, 7 and 8). The PGM and nEA pins control both
the function enable and the pin multiplexing for the KCBM Interface. Table 9.1, below provides the truth
table for the Flash Program Interface Decoder. See Section 9.10, "Flash Program Register".
SMSC LPC47N350
107
Revision 1.1 (01-14-03)
DATASHEET
SMSC [ SMSC CORPORATION ]
