Operation; Lpc Interface Activation; Lpc I/O Cycles - Renesas H8S/2100 Series Hardware Manual

6-bit single-chip microcomputer

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Operation

The LPC interface is activated by setting one of the following bits to 1: LPC3E to LPC1E in

HICR0 and LPC4E in HICR4. When the LPC interface is activated, the related I/O ports (P37 to

P30, P83 and P82) function as dedicated LPC interface input/output pins. In addition, setting the

FGA20E, PMEE, LSMIE, and LSCIE bits to 1 adds the related I/O ports (P81, P80, PB0, and

PB1) to the LPC interface's input/output pins.

Use the following procedure to activate the LPC interface after a reset release.

1. Read the signal line status and confirm that the LPC module can be connected. Also check that

the LPC module is initialized internally.

2. When using channels 1, 2 and 4, set LADR1, LADR2, and LADR4 to determine the I/O

3. When using channel 3, set LADR3 to determine the I/O address and whether bidirectional data

registers are to be used.

4. Set the enable bit (LPC4E to LPC1E) for the channel to be used.

5. Set the enable bits (FGA20E, PMEE, LSMIE, and LSCIE) for the additional functions to be

6. Set the selection bits for other functions (SDWNE, IEDIR).

7. As a precaution, clear the interrupt flags (LRST, SDWN, ABRT, OBF, and OBEI). Read IDR

or TWR15 to clear IBF.

8. Set receive complete interrupt enable bits (IBFIE4 to IBFIE1, ERRIE, and OBEIE) as

There are 12 types of LPC transfer cycle: LPC memory read, LPC memory write, I/O read, I/O

write, DMA read, DMA write, bus master memory read, bus master memory write, bus master I/O

read, bus master I/O write, FW memory read, and FW memory write. Of these, the LPC of this

LSI supports I/O read and I/O write.

An LPC transfer cycle is started when the LFRAME signal goes low in the bus idle state. If the

LFRAME signal goes low when the bus is not idle, this means that a forced termination (abort) of

the LPC transfer cycle has been requested.

Section 20 LPC Interface (LPC)

Rev. 1.00 May 09, 2008 Page 627 of 954

REJ09B0462-0100