P80C557E4 查看數據表（PDF） - Philips Electronics

零件编号

产品描述 (功能)

比赛名单

P80C557E4

Single-chip 8-bit microcontroller

Philips Electronics 

Philips Semiconductors

Single-chip 8-bit microcontroller

Product specification

P83C557E4/P80C557E4/P89C557E4

MOVX @Ri, A

MOVX A, @Ri

255

(XRAMP) = 02 H

0

255

(XRAMP) = 01 H

0

255

(XRAMP) = 00 H

0

767

512

511

MOVX @DPTR,A

MOVX A,@DPTR

256

255

0

Figure 5. Indirect addressing of AUX-RAM (768 Bytes), ARD bit in PCON = 0

6.2.2.1 AUX-RAM Page Register XRAMP

The AUX-RAM Page Register is used to select one of three 256

bytes pages of the internal 768 bytes AUX-RAM for

MOVX-accesses via R0 or R1. Its reset value is (XXXXXX00).

XRAMP (FAH)

7

6

5

4

3

x

x

x

x

x

x: undefined during read, a write operation must write “0” to these locations

Figure 6. AUX-RAM page register.

2

1

0

x

XRAMP1

XRAMP0

Table 3. Description of XRAMP Bits

BIT

SYMBOL FUNCTION

XRAMP.2–7

XRAMP.1

XRAMP.0

XRAMPx

XRAMP1

XRAMP0

reserved for future use

AUX-RAM page select bit 1

AUX-RAM page select bit 0

Table 4. Memory Locations for All Possible MOVX Accesses

ARD1

XRAMP1

XRAMP0

MOVX @Ri,A and MOVX A,@Ri instructions access:

0

0

0

AUX-RAM locations 0 .. 255 (reset condition)

0

0

1

AUX-RAM locations 256 .. 511

0

1

0

AUX-RAM locations 512 .. 767

0

1

1

no valid memory access; reserved for future use

1

X

X

External RAM locations 0 .. 255

MOVX @DPTR,A and MOVX A,@DPTR instructions access:

0

X

X

AUX-RAM locations 0 .. 767 (reset condition)

External RAM locations 768 .. 65535

1

X

X

External RAM locations 0 .. 65535

NOTE:

1. ARD (AUX-RAM Disable) is a bit in the Special Function Register PCON

1999 Mar 02

10

Share Link: