All but the most deeply embedded applications generally require an LCD screen to indicate status, report errors, or indicate the response to a command. Renesas RL78/L12 MCUs include an on-chip LCD driver/controller, making them a natural for consumer and industrial devices that require a fast, low-power MCU with a visual interface.
RL78/L12 MCUs run at up to 24 MHz, consuming just 75 μA/MHz in active mode; 0.64 μA in Halt mode (RTC + LVD); and 0.23 μA in Stop mode (with RAM retention). The LCD circuit adds just another 0.61 μA due to internal voltage boost, a 30% saving over competitive products. The devices resemble an RL78/G13 with less program flash (8-32 KB), SRAM (1.0/1.5 KB), and data flash (2 KB) but comparable low-power and performance specs.
The LCD driver/controller is the key new feature. It supports up to 280 LCD segments (8x35) and 16-levels of contrast, with the pin count and RAM size chosen to match the size of the display. The display drive voltage can be derived by one of three methods: internal voltage boost, external resistance division, or capacitor split, all of which are supported on chip.
It’s one thing to check the RL78/L12 datasheet and another to see the chip in action; the new Renesas YRPBRL78L12 Promotion Board lets you to do just that for $10. The board includes a large LCD screen, and on-chip debugger, free e2studio IDE and KPIT GNU compiler, and a number of example programs, with C source code for each. Example programs include
If a picture may be worth a thousand words, but a video is a lot more compelling. Check out this Renesas video showing the board in action:
And Happy New Year from Dr. Micro!