7721 datasheet(529/577 Pages) RENESAS

Part #	7721

Description	16-BIT SINGLE-CHIP MICROCOMPUTER

PDF	577 Pages

Scroll/Zoom	100%

Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

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529 / 577 page

APPENDIX

Appendix 9. 7721 Group Q & A

7721 Group User’s Manual

17–66

SFR

Is there any SFR to which a certain instruction cannot be used for writing ?

(1) Use the LDM or STA instruction to write to the registers or the bits listed below.

Do not use read-modify-write instructions (i.e., CLB, SEB, ASL, ASR, DEC, INC, LSR,

ROL, and ROR).

Pulse output data register 0, 1 (addresses 1A16, 1C16)

UART0, 1 baud rate register (addresses 3116, 3916)

UART0, 1 transmit buffer register (addresses 3316, 3216, 3B16, 3A16)

Timer A2–A4 two-phase pulse signal processing select bit (bits 5–7 at address 4416)

Timer A2–A4 register (addresses 4A16–4F16 ; one-shot pulse mode or pulse width

modulation mode)

Refresh timer (address 6616)

(2) Use the SEB or CLB instruction to write to the following register.

DMAC control register H (address 6916 ; when any of bits 4 to 7 = “1”)

7721 Datasheet(PDF) 529 Page - Renesas Technology Corp